742 Sentences With "occultation" | Random Sentence Generator

But, given the weather during the occultation night, we were really relieved that the occultation had been observed.

The occultation will take place a little after 11 a.m.

Such a passing causes a momentary eclipse known as an occultation.

The July 693 occultation track mostly passed over the southern Pacific.

The next occultation event between Europa and Io is scheduled for 2021.

It's called occultation, and it's one of the coolest tricks in astronomy.

Recording this eclipse, or occultation as it's more formally known, was no accident.

In Los Angeles, for instance, the occultation will begin at 3:38 a.m.

Skygazers in Denver, for instance, will see the occultation begin at 4:41 a.m.

The star involved in the occultation goes by the catchy name of Gaia DR2 4090460400982698240.

Still, it shows the potential importance of occultation-based methods for finding these dim objects.

That's why the New Horizons team set out to see 2014 MU20143 with an occultation.

"I realized it didn't make any sense, because the occultation star was missing," she said.

For people in New York, the Moon-Mars occultation will start around 7:36 a.m.

Even without this occultation taking place, the gates of information were already beginning to open wide.

Plus, the occultation has also served as a check on the team's work up until now.

That data, gathered using a technique called radio occultation, can gauge atmospheric temperature, moisture and pressure.

Finally, the occultation of Mercury, the planet of communication, suggests a period of truth-seeking is incoming.

During the occultation observed in Senegal we have collected data using telescopes pointed in 21 different sites.

Here are the best places to see the lunar occultations, according to the International Occultation Timing Association.

However, the first two times the scientists tried to see the occultation, they didn't see the object's shadow.

But Spire's employees are optimistic, even if they have to explain radio occultation more often than they'd like.

In what is known as an occultation, Mars will briefly be blocked by the moon on Tuesday morning.

Meanwhile, the occultation of passionate, action-oriented Mars may prompt you to change your approach to a preexisting challenge.

It was a momentary eclipse, known as an occultation, in which Ultima Thule briefly blocked out the star's light.

With the right telescope equipment, the results can be jaw-dropping, like this lunar occultation of Saturn in 2019.

Specially designed Cassini orbits place Earth and Cassini on opposite sides of Saturn's rings, a geometry known as occultation.

And they can now go back and figure out why they didn't see the occultation during the first two attempts.

The only way to find out is more observation—especially during one of the star's now famous periods of occultation.

The rare alignment, formally called an occultation , will let astronomers study light streaming through the layers of Titan&aposs hazy atmosphere.

The occultation revealed that Ultima Thule is either shaped like a rubber duck, looking a bit like two mounds squashed together.

The moon will momentarily block three planets — Venus, then Mars, then Mercury — this week, in what is known as an occultation.

The event is called a lunar occultation, and it occurs whenever the moon passes in front of a faraway celestial object.

If you're in one of the locations that will see an occultation, you're most likely to catch it with a small telescope.

Astronomically speaking, an occultation is when one object moves in front of another object in the sky from our point of view.

Similar to an eclipse, an occultation occurs when one celestial body (in this case, the moon) moves in front of another celestial body.

Although this week's occultation won't be a visual marvel, like last month's solar eclipse, it may have similar, weeklong effects on your life.

North Americans who don't fall under the direct route of the occultation will still get to enjoy partial eclipses, depending on the latitude.

Senegal was chosen to observe this occultation, because of its political stability, and the existence of a community of amateur astronomers and scientists.

On January 21st, the astronomy team observed Haumea's occultation of a distant star — eloquently named URAT1 533-182543 — with 12 different telescopes across Europe.

The duration of a lunar occultation depends on many factors, like what is getting blocked and where on Earth someone is observing it from.

Unfortunately for viewers in San Francisco and the Pacific Northwest, the moon will not be above the horizon before the beginning of the occultation.

It was the Voyager 23 spacecraft that spotted the first solar occultation at Titan in 22, according to a paper published in The Astrophysical Journal.

On July 10, during a different occultation, NASA's airborne Stratospheric Observatory for Infrared Astronomy (SOFIA) detected an apparent short drop-out in the star's light.

A new method called occultation takes a large number of stars and looks for shadows of objects to pass by, which made this discovery possible.

In fact, up to five different telescopes were able to spot the occultation in Argentina, giving the New Horizons team five different angles of the event.

The success also confirmed that the Sofia observations a week earlier had barely missed the occultation and were close enough to the shadow to be useful.

This celestial event is known as a Moon-Mars occultation, and it occurs from some vantage point on Earth about twice a year, according to NASA.

Being able to predict when the occultation would occur — and then see it — means the New Horizons scientists have accurately figured out the orbit of 2014 MU69.

When a planet passes in front of a star it blocks the light causing a brief flicker that can be detected and investigated — this is called "occultation."

And while the agency has had, and will soon have, more radio-occultation smallsats of its own, it's interested in learning whether it could also buy such data.

It gave second contracts to Spire and GeoOptics (which now has some actual satellites), and one to PlanetIQ (which does not, but also plans to use radio occultation).

In order to collect data for this object, the New Horizons team took advantage of a stellar occultation on July, 103, 2017, visible in Argentina and South Africa.

"The [resulting] imprint could be changes in the brightness of the host star due to occultation (similar behavior to Tabby's star) if the structure is big enough," said Loeb.

Last night, the moon passed in front of Venus, and it's now on course to block out Mars and Mercury this evening, in an event known as an occultation.

On the night of the occultation, a major national highway was shut down for two hours to keep car headlights away, and street lights were turned off to reduce lighting.

Click here to view original GIFImage:: NASA/JHUAPL/SwRI"It was the most historic occultation on the face of the Earth," noted NASA planetary scientist Jim Green in a statement.

It wasn't until this weekend, just before midnight Eastern Time on Sunday, that the mission team finally caught the occultation while huddled around telescopes in Chubut and Santa Cruz, Argentina.

The short eclipse — also known as an occultation — was seen with five different telescopes, and gave scientists a ton of new data about 2014 MU69's size, shape, and brightness.

In other cases, like that of Saturn's moon Titan, the angular size of the satellite in the sky is far greater than that of the Sun, resulting in a solar occultation.

NOAA's 2020 budget request includes up to $6 million to purchase radio occultation data from private firms as well as money to continue testing and evaluating the quality of the information.

This phenomenon, called a stellar occultation, lasted just a second and was visible only in certain regions in Africa (more exactly in Senegal, Mali and Algeria) and in South America in Colombia.

It was to find signs of this more widespread material that a spectroscopic instrument called NOMAD (Nadir and Occultation for MArs Discovery), which is on board ExoMars Trace Gas Orbiter, was designed.

The researchers looked for these "occultation" events using a pair of $6,000 Celestron telescopes, each equipped with an astronomy camera and an attachment to increase the camera's maximum aperture size and increase the field of view.

The researchers figured this out by first deducing Cressida's mass, which they were able to do by studying its relationship with one of Uranus's rings using occultation data collected from Earth-based observations and Voyager 2.

It was a momentary eclipse — known as an occultation — and though it lasted just seconds, the sighting will provide useful information about the shape and size of the object that the spacecraft will visit next year.

During an attempt in July to view an occultation from NASA's Sofia observatory, a modified 747 jet that carries a 100-inch telescope, the astronomers did not see anything definitive, but there was a suggestive blip.

"Large occultation surveys, as well as OASES and other small projects by amateur astronomers and citizen scientists, will reveal the nature of small outer Solar System objects hidden in the darkness," the team wrote in the paper.

For lovers of the dark skies, Dr. Faherty said that even after the occultation ends, "the action keeps going," because the crescent moon will swing near Jupiter on Wednesday before dawn and then mosey up to Saturn on Thursday.

Mr Amanat highlights another important point in Iran's politico-religious make-up when he traces the cyclical nature of divine revelation in "Twelver" Shia thought, through the 12 imams (descendants of Prophet Muhammad), and the 12th imam's "occultation" in 874.

Skywatchers from much of North and Central America will have a front-row seat to Tuesday's occultation, and those along part of the West Coast will have an especially good view, with a chance to watch the entire show before sunrise.

And in August of this year, when MU69 conveniently passed in front of a star (an "occultation" event), astronomers realized they're dealing with either an elongated, peanut-shaped object (similar to comet 67P/Churyumov–Gerasimenko), or two asteroids orbiting each other (i.e.

Occultation SelfiesWhen an asteroid passes in front of a star from the point of view of Earth, people with stopwatches scattered around the world can time when the star disappears and reappears, and use those measurements to build up a picture of the asteroid.

Asteroid eclipse rained out Space.com 2014 March 20 The website of the International Occultation Timing Association does not list any successful observations at all.Regulus 2014 International Occultation Timing Association Two single chord Asteroid Occultation events have been observed, in 2013 and 2015.

The Minor Occultation (, ') (874–941 CE), also known as the First Occultation (, '), in Shia Islam refers to the early years of the Imamate of Hujjat-Allah al-Mahdi, who disappeared and would only contact his followers through the Four Deputies. It was followed by the Major Occultation.

All types of eclipses, occultation of stars by planets and asteroids, lunar occultation, transits, timing these events, photography and CCD observations for study of particular Astronomical body.

The occultation of 12th Imam left a considerable gap in leadership of Shias. According to Shia beliefs the Imam was both the spiritual and political head of the community. Although during the lesser occultation the network of Imam deputies (wikala) claimed to have the right to handle Shia communities' issues, this system was not continued during the Greater Occultation. After the greater occultation, the role of Imam as the head of community was left vacant, which did not theoretically matter at the beginning of Occultation because Shias had no political power at that time.

The Major Occultation (, '), according to Shia, is Hujjat-Allah al-Mahdi's second occultation after the Minor Occultation. According to Twelvers, the Major Occultation which came around the year 329AH/941CE is still in effect, and will not end until the end of time when the Mahdi returns to reestablish justice on earth. Upon the death of his father, while still a child, it is believed that the twelfth Imam entered his first occultation which lasted 70 lunar years. During this time the hidden imam is said to have represented on earth by four successive deputies.

Critics say the occultation of the 12th imam "became subsequent orthodox doctrine" after none of the competing theories that sought to explain the succession to a childless 11th Imam "seemed satisfactory". According to Wilferd Madelung, however, the doctrine of the Occultation was well-documented by traditions of the Imams before the occultation.

According to Jassem Hossein, traditions regarding occultation of Mahdi had been collected by many different shia sects. Before 874, the traditions existed in Waqifi, Zaydi, Jarudi and Imamite books. In Waqifis, Anmati Ibrahim ibn Salih Koufi, a disciple of the fifth Imam, wrote a book titled "Occultation". Ali ibn Hossayn Taee Tatari and Hassan ibn Mohammad ibn Sama'ah each wrote a book titled "Book of Occultation" and introduced the seventh Imam as the Imam who will go into Occultation.

A stellar occultation by in December 2018 gave a minimum diameter of 458 km. In 2018, two stellar occultations by were observed on 3 February and 24 December. Observations of the February occultation yielded a single chord length of . Observations of the December occultation yielded two positive chords, which suggest an approximate diameter of for .

The Major Occultation (, ') denotes the second, longer portion of the Occultation, which continues to the present day. Shia believe, based on the last Saf’ir's deathbed message, that the Twelfth Imam had decided not to appoint another deputy. Thus, al-Samarri's death marked the beginning of the second or Major Occultation. According to the last letter of Hujjat-Allah al-Mahdi to Ali ibn Muhammad al-Samarri: > From the day of your death [the last deputy] the period of my major > occultation will begin.

Major GNSS radio occultation missions include the GRACE, CHAMP, and COSMIC.

Al-Mufid received two Tawqees by Muhammad al-Mahdi during major occultation.

This could be done using the occultation of a star by 2I/Borisov but an occultation would be difficult to predict, requiring a precise determination of its orbit, and the detection would necessitate a network of small telescopes.

Many doubts and skeptics existed during the period of Nu'mani about the occultation of Imam Al Mahdi. Many people were skeptics on the subject of Ghaybah. Nu'mani said that he saw that the Shia followers became perplexed on the event of occultation and he tried to save them from this perplexity. Therefore, he began to write a book on the subject of occultation of Imam Mahdi.

GNSS radio occultation (GNSS-RO), historically also known as GPS radio occultation (GPS-RO or GPSRO), is a type of radio occultation that relies on radio transmissions from GPS (Global Positioning System), or more generally from GNSS (Global Navigation Satellite System), satellites.Melbourne et al. 1994. The application of spacebourne GPS to atmospheric limb sounding and global change monitoring. Publication 94-18, Jet Propulsion LaboratoryKursinski et al. 1997.

A small moon about 1 kilometer in diameter was suggested based on occultation data from 29 May 1978. In 1980, speckle interferometry suggested a much larger satellite, whose existence was later refuted a few years later with occultation data.

Occultation of the Twelfth Imam: A Historical Background. Routledge. . By the third and fourth decades of the 10th century (i.e. the closing years of the Lesser Occultation), the majority of the Shias were agreed on the line of the Twelve Imams.

The Global Ozone Monitoring by Occultation of Stars (GOMOS) is a measurement instrument aboard the European satellite Envisat. It measures ozone amounts by using the emitted electromagnetic spectrum from surrounding stars combined with trigonometric calculations in a process called stellar occultation.

The occultation yielded a chord length of , quite large compared to mean diameter estimates from thermal measurements. Because the occultation occurred near Varuna's maximum brightness, the occultation was observing the maximum apparent surface area for an ellipsoidal shape; the longest axis of Varuna's shape was observed during the occultation. São Luís was also located very close to the predicted centerline of Varuna's shadow path, meaning the chord length was close to the longest measurable during the event, closely constraining the possible maximum equatorial diameter. Results from the same event from Camalaú, Paraíba, approximately south (and on what was predicted to be the very southern extent of the shadow path), showed a 28-second occultation, corresponding to an approximately chord, much longer than might otherwise have been expected.

For serious precision timekeeping, a more specialized GPS device is needed. Some amateur astronomers, most notably those who time grazing lunar occultation events when the moon blocks the light from stars and planets, require the highest precision available for persons working outside large research institutions. The Web site of the International Occultation Timing AssociationInternational Occultation Timing Association has detailed technical information about precision timekeeping for the amateur astronomer.

There is one reported stellar occultation by Protogeneia, on May 28, 2002, from Texas.

The next occultation by a planet will be by Venus on February 17, 2035.

Previous attempted observations of stellar occultations by Varuna in 2005 and 2008 were unsuccessful due to uncertainties in Varuna's proper motion along with undesirable conditions for observing. In 2010, an occultation by Varuna was successfully observed by a team of astronomers led by Bruno Sicardy on the night of 19 February. The occultation was observed from various regions in southern Africa and north- eastern Brazil. Although observations of the occultation from South Africa and Namibia had negative results, observations from Brazil, particularly at São Luís in Maranhão, successfully detected a occultation by Varuna of an 11.1 magnitude star.

An occultation on March 19, 1981, suggested a diameter of 219±25 km. Observations of an occultation on October 14, 1999, using four well-placed chords, indicate an ellipsoid of 278×142 km and that 48 Doris is an extremely irregularly shaped object.

At the end of The Minor Occultation, Imam wrote a letter to Abul Hasan Ali ibn Muhammad al-Samarri and informed him about beginning of the major occultation. The signed letter by Hujjat-Allah al-Mahdi was shown in The book Kamāl al-Din by Ebn Bābuya for the first time. During the Major Occultation, the only one who alleged that they received any taqees from Imam al-Mahdi was al-Shaykh al- Mufid.

Ghaybat al-Sughra or Minor Occultation (874–941), consists of the first few decades of the Imam's disappearance when communication with him was maintained through his deputies. Tusi and al-Mofid state that the Occultation resumed on the third or seventh day of his birth.

Observations of an occultation on 21 March 1998, produced several chords indicating an ellipsoidal cross-section of .

Using REX radio occultation data the diameter of Pluto was found to be in a 2017 paper.

Al-Ghaybah () is a theological book by Muhammad Ibn Ibrahim Ibn Jafar al- Numani on the subject of the occultation of the Twelfth Imam of the Twelvers, Hujjat-Allah al-Mahdi. The aim of book returns to the doubtful atmosphere in that period and neediness to proving the occultation by reason and narration.

From the 2011 stellar occultation by Makemake, its dimensions have been initially measured to be . However, the occultation data was later reanalyzed, which led to the dimension estimate of without a pole-orientation constraint. Makemake was the fourth dwarf planet recognized, because it has a bright V-band absolute magnitude of −0.2.

Accommodation is only effective for distances greater than 2 meters. ; Occultation : Occultation (also referred to as interposition) happens when near surfaces overlap far surfaces. If one object partially blocks the view of another object, humans perceive it as closer. However, this information only allows the observer to create a "ranking" of relative nearness.

Bürg is named for Austrian astronomer Johann Tobias Bürg, who discovered Antares's companion star during an occultation event in 1819.

Among Zaydis AbousSaeed Ibad ibn Yaqub Ravajini Asfari in a book titled Aboosaeed Asfari collects traditions on occultation and the twelve Imams and the end of Imams in twelve without naming them all. From the Twelvers, Ali ibn Mahziar Ahwazi who died on or before 874 CE wrote two books titled, Kitab Al-Malahem and Kitab Alqaem both on occultation and the rise of Imam with sword. Hossein ibn Mahboob Sarad wrote the book titled Al-mashikhah on occultation. Fazl ibn Shazan Nisabouri wrote Al-Qaybah which is narrated from Al-Mashikhah.

Diomedes was the first Jupiter trojan that was successfully observed during an asteroid occultation, when it occulted the star HIP 014402A over Japan on 7 November 1997. The silhouette was elongated with a major and minor occultation axis of kilometers (poor fit). The ellipsoid dimensions of kilometers – corresponding to a mean-diameter of 132.5 kilometers, equivalent to the volume of a sphere – were estimated using follow-up photometry at Ondřejov Observatory and Mitaka Observatory that determined the body's rotational phase at the exact time of the occultation event.

The next occultation observed was on 12 June 2006, with later ones occurring more frequently. Processing of these data shows that the pressure continues to increase. An occultation of an exceptionally bright star, about 10 times brighter than the Sun itself, was observed on 29/30 June 2015 – only 2 weeks before the New Horizons encounter. On 14 July 2015 the New Horizons spacecraft made the first explorations of the atmosphere of Pluto from close distance, including radio occultation measurements and observations of weakening of solar radiation during flight through Pluto's shadow.

Social occultation occurs when a particular set of cultural values and beliefs combine with the operation of personal and mass media communication functions leads to lacunae, or blind spots. Intentional social occultation is the process of creating social invisibility while not completely denying the reality of a social circumstance, issue, or problem. Social occultation is a dynamic of social constructionism. For example, the recent abuses by the USA military at Abu Ghraib prison in Iraq were made highly visible and resulted in shock and outrage in the USA.

During this event, the observed brightness was predicted to dip from magnitude 14.7 (star + Chariklo) to 18.5 (Chariklo alone) for at most 19.2 seconds. This increase of 3.8 magnitudes is equivalent to a decrease in brightness by a factor 32.5. The primary occultation event was accompanied by four additional small decreases in the overall intensity of the light curve, which were observed seven seconds before the beginning of the occultation and seven seconds after the end of the occultation. These secondary occultations indicated that something was partially blocking the light of the background star.

An asteroid occultation on 27 October 2005, gave a best-fit ellipse dimension of 69.0 × 69.0 kilometers, while a second occultation event gave an ellipse of 61.0 km × 61.0 km on 3 February 2014, with the latter having a better quality rating. These timed observations are taken when the asteroid passes in front of a distant star.

On 13 June 2005, Takuboku occulted 9.3 magnitude star TYC 0312-00789-1, causing a predicted magnitude drop 6.8 during 4.3 seconds. The occultation was visible over the southern island of New Zealand only. Measurement of the asteroid's occultation dimensions 35.0 ×35.0 for its major and minor best-fit ellipse (the fit's quality code is 1).

However, a 2004 occultation showed a cross- sectional profile of only 48x53 km. Angelina was observed by Arecibo radar in January 2010.

Additional observations in 2011 gave an occultation cross-section with a semi-major and minor axis of 39.3 and 18.9 kilometers, respectively.

This event was observed at 130 locations in the United States and Mexico and was the best observed of all asteroid occultation events.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Alphonsina measures between 54.34 and 63.52 kilometers in diameter and its surface has an albedo between 0.204 and 0.2786. Combined Plot - Light Curve Inversion model (DAMIT 301) and Multi- chord Occultation. In 2003, stellar occultation measured a diameter of 59.2 kilometres and deduced an albedo of 0.218, while the modelling of asteroid occultation silhouettes gave a diameter of 58 kilometres. The asteroid has been observed in stellar occultations 8 times since 2003.

Another small tariqah is the Zaidi Shias, also known as the Fivers and who do not believe in The Occultation of their last Imam. Although all these different Shia tariqahs belong to the Shia group (as opposed to the Sunni group) in Islam, there are major doctrinal differences between the main Shia tariqahs. After that there is the complete doctrinal break between all the different Shia tariqahs whose last Imams have gone into Occultation and the Shia Nizari Ismailis, who deny the concept of Occultation and so have to have a present and living Imam until the end of time.

The first stellar occultation was observed on August 17, 1979, from the Gissar and Alma-Ata observatories produced two chords which were used to estimate a diameter of 150 km for the asteroid. This is close to the present-day estimate of 147.9 km. Since then 51 Nemausa has been observed 20 times in stellar occultation. Light curve inversion model DAMIT 1065 is a good match to a seven-chord occultation observed on 3rd September 2016, from which an equivalent Volume mean diameter of 146.4km, and an equivalent Surface mean diameter of 150.3 km was obtained.

On 24 May 1981, they detected a dip in a star's brightness during one occultation; however, the manner in which the star dimmed did not suggest a ring. Later, after the Voyager fly-by, it was found that the occultation was due to the small Neptunian moon Larissa, a highly unusual event. In the 1980s, significant occultations were much rarer for Neptune than for Uranus, which lay near the Milky Way at the time and was thus moving against a denser field of stars. Neptune's next occultation, on 12 September 1983, resulted in a possible detection of a ring.

University of Southern California. 18 June 2012. Sachedina also states that the idea of the eschatalogical Qa'im who would rise after going to occultation was mentioned by fifth and sixth Imams, Muhammad al-Baqir and Ja'far al-Sadiq, at various times when the two were approached by their followers and assured them of their support, if they wanted to rise against the existing regime. After the greater occultation, the role of Imam as the head of community left vacant, which did not theoretically matter at the beginning of Occultation because Shias had no political power at that time.

Thisbe, minor planet designation 88 Thisbe, is the 13th largest main-belt asteroids. It was discovered by C. H. F. Peters on June 15, 1866, and named after Thisbe, heroine of a Roman fable. An occultation of a star by Thisbe was observed on October 7, 1981. Results from the occultation indicate a larger than expected diameter of 232 km.

Twelver Shias believe that the Imam did not suffer death, but that, for various reasons, has been concealed by Allah from mankind. This event is known as "The Occultation". Since the year AH 329 (about 940 CE), the occultation has been divided into two periods. The Quran states, that there are two kinds of saints of God among people: apparent and hidden.

According to Waqifi Sevener Shias, there are reasons for the occultation: Imam not being proud of himself and continue to examine world events and make evaluations, only to be loyal and reverent to the Lord and Allah, which are also in Occultation, the other Muslims sects are to be judged by the Mahdi through the guidance of the Lord and Allah.

IRAS measurements in 1983 estimated the asteroid to be 317 ± 5 km in diameter. An occultation in 1996 produced a diameter of 329 km. Observations of a favorable occultation of a bright 6.6 magnitude star on March 23, 2003, produced thirty-five chords indicating an ellipsoid of 350×304 km, thus giving the asteroid a geometric mean diameter of 326 km.

During later occultations (when the atmosphere of Pluto was already denser) this kink was absent. Another evidence of the haze was obtained in 2002 due to a new occultation. The stellar light which managed to reach Earth during the occultation (due to refraction in Pluto's atmosphere), demonstrated an increase of intensity with wavelength.At least, in infrared range — from 0.75 to 2 µm.

The Voyager 2 spacecraft observed a strange signal from the ε ring during the radio occultation experiment. The signal looked like a strong enhancement of the forward- scattering at the wavelength 3.6 cm near ring's apoapsis. Such strong scattering requires the existence of a coherent structure. That the ε ring does have such a fine structure has been confirmed by many occultation observations.

An example of an occultation is when the Moon passes between Earth and the Sun, causing the Sun to disappear either entirely or partially. This phenomenon is commonly known as a solar eclipse. Occultations in which the larger body is neither the Sun nor the Moon are very rare. More frequent, however, is an occultation of a planet by the Moon.

Shia tradition cites four major reasons for Mahdi's occultation: protecting the life of the Imam; independence with regard to temporal powers; testing Shi'as in order to measure their faith; and also there is a secret reason which won't be revealed until the end of time. The real reason for the Occultation, according to a Hadith, will be known when the Imam re-appears.

They were Uthman ibn Sa'id al-Asadi, Abu Jafar Muhammad ibn Uthman, Abul Qasim Husayn ibn Ruh al-Nawbakhti, Abul Hasan Ali ibn Muhammad al-Samarri. After the death of the fourth deputy, the Imam did not appoint a new deputy and the Major Occultation begun. According to Shia belief, al-Mahdi did not die, but rather continues living in occultation.

Before Minor Occultation he was the deputy of Ali al-Hadi, the tenth Imam of Shia and Hasan al-Askari the eleventh Imam of Shia.

Another occultation on 21 October 2012, gave an ellipse of (). These timed observations are taken when the asteroid passes in front of a distant star.

Four separate stellar occultation events involving this asteroid were observed from multiple sites in 2009. The resulting chords matched a least squares equivalent diameter of .

An occultation of Mars by Venus on 13 October 1590 was observed by the German astronomer Michael Maestlin at Heidelberg. The 1737 event (see list below) was observed by John Bevis at Greenwich Observatory – it is the only detailed account of a mutual planetary occultation. A transit of Mars across Jupiter on 12 September 1170 was observed by the monk Gervase at Canterbury, and by Chinese astronomers.

Resolved images of Himalia by Cassini have led to a size estimate of , while ground- based estimates suggest that Himalia is large, with a diameter around . In May 2018, Himalia occulted a star, allowing for precise measurements of its size. The occultation was observed from the US state of Georgia. From the occultation, Himalia was given a size estimate of , in agreement with earlier ground-based estimates.

The last occultation of Regulus by a planet was on July 7, 1959, by Venus. The next will occur on October 1, 2044, also by Venus. Other planets will not occult Regulus over the next few millennia because of their node positions. An occultation of Regulus by the asteroid 166 Rhodope was observed by 12 researchers from Portugal, Spain, Italy, and Greece on October 19, 2005.

An occultation on 29/30 June 2015, just 2 weeks before New Horizons encounter, provided a surface pressure of . The first direct and reliable data about the lowermost layers of the atmosphere of Pluto were obtained by New Horizons on 14 July 2015 due to radio-occultation measurements. The surface pressure was estimated to be ( at entry of the spacecraft behind Pluto and at the exit).

Since it is near the ecliptic, Nu Scorpii can be occulted by the Moon and, very rarely, by planets. Mercury occulted it on 14 December 1821, but will not occult it again until 2 December 2031. The last occultation by Venus took place on 27 December 1852 and the next will take place on 30 December 2095. On 29 July 1808 there was an occultation by Neptune.

In 1972, a team of Indian, British and American astronomers working in Java (Indonesia) and Kavalur (India) claimed that they had detected a thin atmosphere during an occultation, when it and Jupiter passed in front of a star. They estimated that the surface pressure was around 0.1 Pa (1 microbar). However, in 1979, Voyager 1 observed an occultation of the star κ Centauri during its flyby of Jupiter, with differing results. The occultation measurements were conducted in the far-ultraviolet spectrum at wavelengths shorter than 200 nm, which were much more sensitive to the presence of gases than the 1972 measurements made in the visible spectrum.

A possible third component with an apparent magnitude of +9.5, detected by studying the star during occultation, is located 0.052 arcseconds away from the A component.

The primary is listed as being double following observations of a lunar occultation, but later observations have failed to find any evidence of it being double.

The Major Occultation began following the death of the last deputy and, according to the Shia doctrine, will continue until the return of the Mahdi(a.s).

Two 30-amp-hour, nickel-cadmium, rechargeable batteries provided power when the spacecraft was not facing the Sun, and during launch, correction maneuvers and Mars occultation.

The ǂKá̦gára–ǃHãunu system is currently undergoing mutual occultation and eclipsing events in which one body casts its shadow upon or obstructs the view of the other.

In 2015 members of the society recorded an important Pluto occultation on 29 June 2015 a couple of weeks before the New Horizons fly by of Pluto.

Reciting Du'a Nudba in the Jamkaran Mosque Du'a Nudba is one of the major Shiite prayers about Muhammad al-Mahdi and his occultation. Nudba means to cry and Shiites read the prayer to ask for help during the occultation. The supplication is recited during Eid al-Fitr, Eid al-Adha, Eid al-Ghadeer, and every Friday morning. Mazar al-Kabir, Mazar al-Ghadim, and Mesbaho al-Zaer were narrated the supplication.

Follow-up observations by Warner in February 2009 gave a concurring period of hours and an amplitude of 0.12 magnitude () with no indications of mutual occultation/eclipsing events.

FORMOSAT-3/COSMIC used as atmospheric sounding. Radio occultation (RO) is a remote sensing technique used for measuring the physical properties of a planetary atmosphere or ring system.

The occultation of Alhena (γ Geminorum) by Myrrha was observed in Japan and China on January 13, 1991, allowing the size and shape of Myrrha to be clarified.

He published a more detailed account of the method in 1717. A longitude determination using the occultation of a planet, Jupiter, was described by James Pound in 1714.

On 12 November 2007, an occultation suggested that Inanda could be a binary asteroid. However, the asteroid's suspected binary nature has not been mentioned in other studies since then.

The fairly flat Irenian lightcurves indicate somewhat spherical proportions. There have been seven reported stellar occultation events by Irene. The best is a three chord event observed in 2013.

In June 2012, the band reformed and released its first new single in 23 years via Slumberland Records and Occultation Records, followed by a second new single in 2014.

Felicitas (minor planet designation: 109 Felicitas) is a dark and fairly large main-belt asteroid. It was discovered by German-American astronomer C. H. F. Peters on October 9, 1869, and named after Felicitas, the Roman goddess of success. The only observed stellar occultation by Felicitas is one from Japan (March 29, 2003).Observed minor planet occultation events, version of 2005 July 26 During 2002, 109 Felicitas was observed by radar from the Arecibo Observatory.

GOMOS (Global Ozone Monitoring by Occultation of Stars) looks at stars as they descend through the Earth's atmosphere and change color, allowing measurement of gases such as ozone (), including their vertical distribution. GOMOS uses the principle of occultation. Its sensors detect light from a star traversing the Earth's atmosphere and measures the depletion of that light by trace gases nitrogen dioxide (), nitrogen trioxide, (), ), ozone () and aerosols present between about altitude. It has a resolution of .

In 1984 an occultation of a star produced seven chords that Kristensen used to derive an ellipsoidal profile of 210×170 km. On 6 August 1989, Metis occulted a magnitude 8.7 star producing five chords suggesting a diameter of 173.5 km. Observations of an occultation on 11 February 2006, produced only two chords indicating a minimum diameter 156 km. (Chords) All three of these occultations fit the ellipsoid 222×182×130 km suggested by Baer.

On 10 September 2018, Varda's projected diameter was measured to be via a stellar occultation, with a projected oblateness of . The equivalent diameter is 746 km, consistent with previous measurements. Given Varda's equivalent diameter derived from the occultation, its geometric albedo is measured at 0.097, making it as dark as the large plutino . Varda's bulk density is constrained around , though the large uncertainty in its rotation period yields various solutions for its density and oblateness.

They planned to use the occultation of the star SAO 158687 by Uranus to study the planet's atmosphere. When their observations were analysed, they found that the star disappeared briefly from view five times both before and after it was eclipsed by the planet. They deduced that a system of narrow rings was present. The five occultation events they observed were denoted by the Greek letters α, β, γ, δ and ε in their papers.

Via asteroid occultations: Observations of an occultation of a bright 5.5 magnitude star on 17 September 2002, produced seventy-five chords indicating an ellipsoid of 111×90 km. (Chords) Observations of an occultation on 15 November 2005, near Grass Valley, CA, produced five chords indicating an incomplete outline of 126×111 km. This larger result may be caused by a different orientation of the asteroid as it passed in front of the star.

NOMAD is one of four science instruments on board the European ExoMars TGO orbiter. This spectrometer consists of three separate channels: solar occultation (SO), limb nadir and occultation (LNO), and ultraviolet and visible spectrometer (UVIS). The first two channels work in the infrared (2.2 to 4.3 μm); the third channel (UVIS) works in the UV-visible range (0.2 to 0.65 μm), which is able to measure ozone, sulphuric acid, and perform aerosol studies.ExoMars NOMAD instrument.

An occultation diameter of ~170 km was measured from the observations. Since then two more occultations have been observed, which give an estimated mean diameter of ~150 km for diameter.

Additionally, the radio system can be used for gravitational and radio occultation studies. The lunar orbiting module was battery-powered and communications were via 183 MHz and 922 MHz aerials.

772 Tanete is an asteroid from the asteroid belt. Since 2004 it has been observed in stellar occultation four times. Its size is best described by an ellipsoid measuring x .

Burnam's Celestial Handbook, pp. 1107-1108. Due to its position on the ecliptic, it is sometimes obscured by the Moon or planets. A lunar occultation took place April 4, 2012.

Australian amateur astronomer Jonathan Bradshaw recorded an unusual asteroid occultation by 32 Pomona on 16 August 2008. The expected maximum duration of the occultation was 7.1 secs; however, the video recording shows two separate occultations of equal depth each lasting 1.2 seconds, separated by 0.8 secs. Those durations convert to chord lengths at the asteroid of 15 km, 10 km, and 15 km – for a total length of 40 km. The IRAS diameter for Pomona is 80.8 ± 1.6 km.

CE Tauri lies 4.6 degrees off the ecliptic. This makes it a candidate for occultations by the Moon and (extremely rarely) by one of the bright planets. The star's angular diameter has been measured by lunar occultation, giving limb-darkened visible light angular diameters of , , and . An occultation has also been observed in H-alpha, giving a diameter of , which indicates that there is circumstellar hydrogen producing emission across at least that size, nearly twice the visible diameter.

The Stratospheric Aerosol and Gas Experiment (SAGE) is a series of remote sensing satellite instruments used to study the chemical composition of earth's atmosphere. Specifically, SAGE has been used to study the Earth's ozone layer and aerosols at the troposphere through the stratosphere. The SAGE instruments use solar occultation measurement technique to determine chemical concentrations in the atmosphere. Solar occultation measurement technique measures sunlight through the atmosphere and ratios that measurement with a sunlight measurement without atmospheric attenuation.

Happelia (minor planet designation: 578 Happelia) is a minor planet orbiting the Sun. On 24 February 2017 a possible small 3-kilometer moon was found orbiting the asteroid, based on occultation observations.

The Taiwanese–American Occultation Survey (TAOS) is a robotic survey of the Outer Solar System. Lehner, M. J.; Wen, C.-Y.; Wang, J.-H.; Marshall, S. L.; Schwamb, M. E.; Zhang, Z.-W.

When a planet has a heliacal rising, there is a conjunction with the Sun beforehand. Depending on the type of conjunction, there may be a syzygy, eclipse, transit, or occultation of the Sun.

However the observations of a stellar occultation in January 2017 cast a doubt on all those conclusions. The measured shape of Haumea, while elongated as presumed before, appeared to have significantly larger dimensions according to the data obtained from the occultation Haumea is approximately the diameter of Pluto along its longest axis and about half that at its poles. The resulting density calculated from the observed shape of Haumea was about more in line with densities of other large TNOs.

He explained the possibility of Occultation by providing rational reasons and hadiths. When Muhammad ibn Uthman was about to die, he introduced Husayn ibn Ruh as his successor. 4) Abu al-Hasan Ali ibn Muhammad al-Samarri () (938–941) : According to a historical view, only deputies had been accepted by the public during the time of the Nawwbakht family and this acceptance had become a week at the time of the al-Samarri. Following his death, the Major Occultation began.

A diagram of the HALOE instrument. HALOE uses solar occultation to measure simultaneous vertical profiles of ozone (O3), hydrogen chloride (HCl), hydrogen fluoride (HF), methane (CH4), water vapor (H2O), nitric oxide (NO), nitrogen dioxide (NO2), temperature, aerosol extinction, aerosol composition and size distribution versus atmospheric pressure at the Earth's limb. The measurements are done at eight different wavelengths of infrared across a wide field of view of Earth's limb. A vertical scan of the atmosphere was obtained by tracking the sun during occultation.

In Islam, the Mahdi is a messianic figure who is believed to be a descendant of Muhammad who will return near the end of time to restore the world and the religion of God. While both Sunni and Shiʻa groups believe in the Mahdi, the largest Shiʻa group, the Twelvers, believe that the Mahdi is the Twelfth Imam, Muhammad al- Mahdi, who is believed to have gone into occultation since 874 CE. In the Twelver view the Twelfth Imam first went into a "Minor Occultation" between 874 and 941 CE where the Hidden Imam still communicated with the community through four official intermediaries. The "Greater Occultation" is then defined from the time when the Hidden Imam ceased to communicate regularly until the time when he returns to restore the world.

Existence of the atmosphere of Pluto was proven via stellar occultation. If a star is occulted by a body without an atmosphere, its light disappears sharply, but occultations by Pluto show a gradual decrease.

Aëria has been observed by astronomers during at least two occultation events: the first in December 2015 and the other in February 2018. These provided information on the size and shape of the asteroid.

Since 1991, the asteroid has been observed in stellar occultation a total of 6 times, all but one were single chord occultations. A 2006 double chord observation indicated a diameter of 126.6 +/-8.3 km.

A 2012 occultation produced a 2D shape model of roughly (with an irregular, skewed outline) and are suggestive of Agamemnon to have a satellite of approximately kilometers in diameter orbiting at from the primary's center.

In Twelver Shia Islam, the largest branch of the Shia faith, twelfth imam, Hujjat-Allah al-Mahdi, went into the Minor Occultation in 874, in which he communicated to his Shias through the Four Deputies.

Brosch discovered the atmosphere of Pluto in 1985 by observing the occultation of a star by the then-considered outermost planet in the Solar System. This observation was analyzed in a paper published much later.

He presented the concept as necessary to protect and preserve Islam during the Occultation of the Imam. According to Khomeini, society should be governed by those who are the most knowledgeable about Islamic law (Shari'ah).

It was occulted by Venus on October 25, 1947; the next occultation by a planet will be by Mercury on 10 November 2052.Peuschel, Marco (2003). "Astronomische Ereignisse der besonderen Art" . Retrieved July 10, 2005.

Belgian Institute for Space Aeronomy. Accessed: 13 August 2018. Measurements are carried out during solar occultation, i.e. the instrument points toward the sunset as the orbiter moves toward or away the dark side of Mars.

Global Ozone Monitoring by Occultation of Stars (GOMOS), is an instrument on board the European satellite Envisat launched 1 March 2002. It is the first space instrument dedicated to the study of the atmosphere of the Earth by the technique of stellar occultation. The spectrum of stars in the ultraviolet, visible and the near infrared parts of the electromagnetic spectrum is observed. It is aimed to use GOMOS to build a climatology of ozone and related species in the middle atmosphere (15 to 100 km).

In addition to the radar data, Magellan collected several other types of scientific measurements. These included detailed measurements of the Venus gravitational field, measurements of the atmospheric density, and radio occultation data on the atmospheric profile.

In 2002, a diameter estimate of 37.93 ± 3.17 km was obtained from the Midcourse Space Experiment observations, with an albedo of 0.2523 ± 0.0448. A stellar occultation by Urda was observed from Japan on July 23, 2001.

During the photometric observations in 2008, the astronomers came across strong evidence that Gingasen is likely an asynchronous binary asteroid with an asteroid moon orbiting it every 3.1095 hours. However, no mutual occultation/eclipse events were observed.

Akhbaris contend that, over the course of the history of Twelver Shi'ism since the Occultation, Usuli ulama have progressively usurped more and more of the functions of the Hidden Imam. They distinguish five stages in this usurpation.

The first Cybelian stellar occultation was observed on 17 October 1979, in the Soviet Union. The asteroid appeared to have an irregular shape, with the longest chord being measured as 245 km, closely matching results determined by the IRAS satellite in 1983 (see below). During the same 1979 occultation, a hint of a possible 11 km wide minor-planet moon at 917 km distance was detected, but has since never been corroborated. As of 2017, neither the Asteroid Lightcurve Data Base nor Johnstons archive consider Cybele to be a binary asteroid.

He died two months before the 11th Imam and declared the twelfth Imam as the Qaem. Yaan Richard suggests occultation was a "convenient solution" for the last Imams' justification of their quietism. According to Sachedina, however, the idea of the eschatological Qa'im who would rise after going to occultation was mentioned by the fifth and sixth Imam, i.e. Muhammad al-Baqir and Ja'far al-Sadiq at various times when the two were approached by their followers and assured of their support if they wanted to rise against the existing regime.

During the period from 1967 to 1969, the European Space Research Organisation (ESRO) studied two separate missions: a European X-ray observatory satellite, as a combined X- and gamma-ray observatory (Cos-A), and a gamma-ray observatory (Cos-B). Cos-A was dropped after the initial study, and Cos-B was proceeded with. Later in 1969 a separate satellite (the Highly Eccentric Lunar Occultation Satellite - Helos) was proposed. The Helos mission was to determine accurately the location of bright X-ray sources using the lunar occultation technique.

Most of his followers followed al- Sadiq's son Musa al-Kazim down to a twelfth and final imam who supposedly went into occultation in 874 and would one day return as the . This branch is hence known as the "Twelvers". Others followed other sons, or even refused to believe that al-Sadiq had died, and expected his return as the . Another branch believed that Ja'far was followed by a seventh imam, who also had gone into occultation and would one day return; hence this party is known as the "Seveners".

Abu al-Hasan Ali ibn Muhammad al-Samarri (, ', died 941 AD) was the fourth and last of the Four Deputies appointed by the twelfth and final Imam, Hujjat- Allah al-Mahdi,The fourth deputy of Imam Zaman (Mahdi) seratnews.com Retrieved 6 Oct 2018 while he was in the Minor Occultation. He became the fourth deputy upon the death of his predecessor Abu al-Qasim al-Husayn ibn Ruh al-Nawbakhti. Unlike the three previous deputies, he had no appointed successor and the Major Occultation began after his death.

Depiction of Chiron with rings. Chiron possibly has rings, similar to the better-established rings of 10199 Chariklo. Based on unexpected occultation events observed in stellar- occultation data obtained on 7 November 1993, 9 March 1994, and 29 November 2011, which were initially interpreted as resulting from jets associated with Chiron's comet-like activity, Chiron's rings are proposed to be in radius and sharply defined. Their changing appearance at different viewing angles can largely explain the long-term variation in Chiron's brightness and hence estimates of Chiron's albedo and size.

This later developed into the doctrine known as the occultation. The Mahdi appeared in early Shi'ite narratives, spread widely among Shi'ite groups and became dissociated from its historical figure, Muhammad al-Hanafiyyah. During the 10th century, based on these earlier beliefs, the doctrine of Mahdism was extensively expanded by Al-Kulayni, Ibrahim al-Qummi and Ibn Babawayh. In particular, in the early 10th century, the doctrine of the occultation, which declares that the Twelfth Imam did not die but was concealed by God from the eyes of men, was expounded.

On 7 August 2008, an asteroid occultation of Pickeringia gave a best-fit ellipse dimension of (), with a poor quality rating of 1. These timed observations are taken when the asteroid passes in front of a distant star.

Based upon an annual parallax shift of 28.79 mas, the distance to this system is approximately . The system is located near the ecliptic, so it is subject to occultation by the Moon. The dynamical mass of the system is .

Al-Nu'mani states two reasons for the Occultation in particular: a) a test for the followers of the Imam and their faith, b) saving the Imam from Bay'a (allegiance) to the oppressive leaders. With all that said, a Hadith states that the real reason for the Occultation will be only known when the Imam re-appears as in the story of Musa and Khidr where the reasons for Khidr's deeds were not immediately revealed to Musa. When Jabir asked Muhammad about the benefits of the hidden Imam, he replied that the people would benefit from his authority (Walayah) as they benefit from the sun when it is covered by the clouds. Sharif al-Murtaza, a classical Shia scholar has argued that the reason for the Imam's Occultation was to protect his life after establishing the just state had been rendered impossible by his enemies.

In Twelver Shiʻa Islamic belief there were twelve Imams, the last of which, known as Imam Mahdi, who communicated with his followers only through certain representatives. According to the Twelver's belief, after the last of these representatives died, the Imam Mahdi went into a state of Occultation; while still alive, he was no longer accessible to his believers. Shiʻa Muslims believe that when the world becomes oppressed, the Imam Mahdi (also termed the Qa'im) will come out of occultation and restore true religion on Earth before the cataclysmic end of the world and judgement day. In Bábí belief the Báb is the return of the Imam Mahdi, but the doctrine of the Occultation is implicitly denied; instead the Báb stated that his manifestation was a symbolic return of the Imam, and not the physical reappearance of the Imam Mahdi who had died a thousand years earlier.

The most likely explanation for this observation is that the asteroid is either binary (including a contact binary), or is a unitary asteroid with a significant concave region on its surface. The video of this occultation can be viewed on YouTube.

There have been 9 occultation events observed since 1987, many of which produced two or three chords. Two examples shown here. 511 Davida occulted TYC 5597-01223 on 5 August 2016. Two observers recorded the event and both observed step events.

Ooty Occultation observations of the galactic centre source, Sgr-A, yielded the first 2-dimensional separation of its thermal and non-thermal emission. During the 1980s, Swarup studied characteristics of jets, cores and hot spots of quasars based on polarisation observations.

4 November 2016. Accessed: 13 August 2018. Since 9 April 2018, NOMAD is measuring the existing atmospheric concentrations of gases, their temperature and total densities. The NOMAD Spectrometer Suite for Nadir and Solar Occultation on the ExoMars Trace Gas Orbiter.

Ghaybat al-Kubra or Major Occultation began 941 CE and is believed to continue until a time decided by Allah, when the Mahdi will reappear to bring absolute justice to the world. According to the last letter of al-Mahdi to Ali ibn Muhammad al- Samarri "from the day of your death [the last deputy] the period of my major occultation (al ghaybatul kubra) will begin. Henceforth, no one will see me, unless and until Allah makes me appear." Another view is that the Hidden Imam is on earth "among the body of the Shia" but "incognito".

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide- field Infrared Survey Explorer with its subsequent NEOWISE mission, Oulu measures between 65.00 and 91.05 kilometers in diameter, and its surface has an albedo between 0.031 and 0.06. The Collaborative Asteroid Lightcurve Link agrees with IRAS, that is, an albedo of 0.0366 and a diameter of 82.72 kilometers using an absolute magnitude of 9.62. In May 2002, Vasilij Shevchenko and Edward Tedesco observed an occultation by Oulu, that gave a diameter of 65.0 kilometers with an occultation albedo of 0.0594.

Alkeste (minor planet designation: 124 Alkeste) is a large main-belt asteroid, and it is an S-type (silicaceous) in composition. C.H.F. Peters discovered the asteroid on August 23, 1872, from the observatory at Hamilton College, New York State. The name was chosen by Adelinde Weiss, wife of the astronomer Edmund Weiss, and refers to Alcestis, a woman in Greek mythology. The observed shape of Alkeste from a stellar occultation in 2003 A 20 chord stellar occultation by Alkeste was observed when the asteroid passed in front of the third magnitude star Beta Virginis on June 24, 2003.

The Astronomical League awarded Edward Halbach with the Astronomical League Award in 1972. Halbach was the first living recipient of the Leslie C. Peltier Award in 1981 for his variable star and lunar occultation observations and contributions to artificial satellite programs. The American Association of Variable Star Observers honoured him with the Merit Award in 1988, for his record of more than 50,000 observations in the AAVSO International Database and for 54-year service in the society. He also won the Amateur Achievement Award of the Astronomical Society of the Pacific for his variable star and occultation observations in 1997.

Twelver Shia Muslims believe that the 12th Imam, Muhammad al-Mahdi, is currently living and is removed from access by his followers in a state called the major occultation. In Twelver belief, the 12th Imam is identical with the figure of the Mahdi whose appearance is still awaited by other Muslim sects. It is believed that before the Day of Judgement, Muhammad al-Mahdi will return with a group of chosen companions. This return is more properly known as zuhur or 'appearance', as the Hidded Imam is believed to have remained alive during his occultation since the year 874.

Pallas has been observed occulting stars several times, including the best-observed of all asteroid occultation events, by 140 observers on 29 May 1983. These measurements resulted in the first accurate calculation of its diameter. After an occultation on 29 May 1979, the discovery of a possible tiny satellite with a diameter of about 1 km was reported, which was never confirmed. Radio signals from spacecraft in orbit around Mars and/or on its surface have been used to estimate the mass of Pallas from the tiny perturbations induced by it onto the motion of Mars.

This is consistent with occultation data from previous years, although some of the previous calculations based on this data gave about 2 times higher results. The stellar occultation 17 July 2019 have shown the Pluto`s atmospheric pressure have dropped about 30% from maximal values in 2015, reaching 0.967 Pa. The scale height of pressure in Pluto's atmosphere varies significantly with height (in other words, the height dependence of the pressure deviates from exponential). This is caused by strong height variations of temperature. For the lowermost layer of the atmosphere the scale height is about , and for heights — .

Because an occultation event for an individual object is quite rare, the process of observing occultation events begins with the creation of a list of candidate targets. The list is generated from a computer by analyzing the orbital motions of a large collection of objects with known orbital parameters. Once a candidate event has been chosen whose ground track passes over the site of an observer, the preparations for the observation begin. A few minutes before the event is expected to happen the observing telescope is targeted to the target star and the star's lightcurve is recorded.

Later occultations in 2013 and 2014 yielded mean diameters of and , respectively. The mean diameter of , calculated from both chords from the occultations, appears seemingly consistent with the Spitzer and Herschel thermal measurement of . While the apparent oblateness of Varuna could not be determined from the single chord obtained from the 2014 occultation, the 2013 occultation yielded two chords, corresponding to an apparent oblateness of approximately 0.29. The imposed oblateness for the 2013 chord length of as Varuna's diameter corresponds to a polar dimension of approximately , somewhat consistent with the calculated 2010 minimum polar dimension of .

In all the Sunni traditions, the Imamim-Mubeen is interpreted as the Quran itself; and in all the Shia traditions, except the Shia Nizari, the Imamim-Mubeen is the last Imam of a dynasty that went into occultation. However, in Nizari Ismailism, the Imamim-Mubeen is a living human Imam who is never in occultation, who will never ever be absent from this world but will always be perpetually present and physically alive, and who is designated as the inheritor of an Imamate passed down from father to son. This tradition has continued for almost 1400 years.

In 2001, the asteroid was detected by radar from the Arecibo Observatory at a distance of 1.18 AU. The resulting data yielded an effective diameter of . An Occult (Software) plot of 5 Occultation chords (and a miss) with DAMIT Inversion model at event time. There have been 9 occultation observations of this asteroid since 2004. The latest of 2018 May 12 was a 5 chord observation that allows, using Occult (Software), the scaling of the DAMIT model 1207, to yield a Mean volume- equivalent diameter of 137.5km and a Mean surface-equivalent diameter of 140.0 km.

Occultation of the Twelfth Imam: A Historical Background. Routledge. . According to Modarressi, the introduction of the idea of the Mahdi have taken place very slowly after the death of the eleventh Imam, and the crisis of succession that resulted from it. According to the Imami doctrine that took shape in the 10th and 11th centuries, the Twelfth Imam is the Mahdi, who is in occultation and will reappear at the end of time. This picture can be supplemented by the early Imami Shia traditions which present the Qa'im as the redresser of the house of Muhammad.

The primary force behind Ahmad's teachings is the belief in the occultation of the Twelfth Imam. Believers in this doctrine, known as Twelvers, hold that the last divine ordained leader, or Imam, lives in occultation and will reappear as the promised Mahdi. Following the Mahdi's appearance, Ahmad teaches that the Imam Hussain ibn Ali will return to re- conquer the world and that the Imam Ali and prophet Muhammad will kill Satan. Al Raj'a (meaning "the return" in English) was heavily emphasized by Ahmad and is more important in Shaykhism in than in the Usuli school of Islam.

It was predicted that 449 occulted the star HIP 1424 in July 2013.Asteroid Occultation Updates Stellar occultations can allow a chord to be calculated An asteroid occulation was predicted for 18 Oct 2018 with the magnitude 12 star UCAC4-557-042266.

The RA and declination for this event was about 00 37 13.64 +28 22 23.2.: detailed information for observers was made available. The occultation produced a diameter of , suggesting an albedo of about 0.88. Mike Brown lists it as a possible dwarf planet.

Wang, C.-Y. Wen First Results From The Taiwanese-American Occultation Survey (TAOS) The Astrophysical Journal, Volume 685, Issue 2, pp. L157-L160. and to Sedna-like objects. The TAOS telescopes are located in Taiwan, at the Lulin Observatory in Yushan National Park.

The first theological tracts on the occultation appeared about thirty years after the death of the eleventh Imam. This idea adopted later by all Imamis, as a result of the efforts of al-Nu'mani and Ibn Babawayh, and some other shia scholars.

The wikalah (singular: wikilah; ) were a networks of agents who were active from Ja'far al-Sadiq's time until the end of the Minor Occultation in 941 CE. The wikalah was responsible for the relations between imams and Shia Islam as well as collecting religious taxes.

The occultation path crossed central Europe along a band that ran through Stockholm, Copenhagen, Bremen, Nantes and Bilbao. This is a member of the dynamic Maria family of asteroids that were probably formed as the result of a collisional breakup of a parent body.

Furthermore, in his earlier works he clearly refers to the temporal Sunni rulers as the "leader of the age" (while stating that the Twelver Shi'a believe this is Muhammad bin Hasan who is in occultation) and wrote openly anti-Twelver commentaries from an Ash'arite perspective.

Path of occultation from New York to Ontario In the early morning hours of March 20, 2014, Erigone occulted the first-magnitude star Regulus as first predicted by A. Vitagliano in 2004. This would have been a rare case of an occultation of a very bright star visible from a highly populated area, since the shadow path moved across New York state and Ontario, including all five boroughs of New York City. Observers in the shadow path would have seen the star wink out for as long as 14 seconds. However, heavy clouds and rain blocked the view for most if not all people on the shadow path.

A notable example of this occurred in 2002 when the asteroid 345 Tercidina underwent a stellar occultation of a very bright star as seen from Europe. During this event a team of at least 105 observers recorded 75 chords across the asteroid's surface allowing for a very accurate size and shape determination. (Chords) In addition to using a known orbit to determine an objects size, the reverse process can also be used. In this usage the occulting object's size is taken to be known and the occultation time can be used to determine the length of the chord the background object traced across the foreground object.

It confirmed that occasional occultation events observed before were indeed caused by the arcs within the Adams ring (see below). After the Voyager fly-by the previous terrestrial occultation observations were reanalyzed yielding features of the ring's arcs as they were in 1980s, which matched those found by Voyager 2 almost perfectly. Since Voyager 2s fly-by, the brightest rings (Adams and Le Verrier) have been imaged with the Hubble Space Telescope and Earth-based telescopes, owing to advances in resolution and light-gathering power. They are visible, slightly above background noise levels, at methane-absorbed wavelengths in which the glare from Neptune is significantly reduced.

Twelver Shiʻi Muslims regard the Twelfth Imam, Muhammad al-Mahdi, as the last of the Imams. They contend that Muhammad al-Mahdi went into the Occultation in 874 CE, at which time communication between the Imam and the Muslim community could only be performed through mediators called Bābs "gates" or Nā'ibs "representatives". In 940, the fourth nā'ib claimed that Imam Muhammad al- Mahdi had gone into an indefinite "Grand Occultation", and that he would cease to communicate with the people. According to Twelver belief, the Hidden Imam is alive in the world, but in concealment from his enemies, and that he would only emerge shortly before the Last Judgment.

As a result of a 1997 lunar occultation, a companion star was discovered at an angular separation of 21 mas. It appears to be an A-type main sequence star with a class of around A5. This companion was not detected during prior occultations by the Moon.

On April 6, 2010, 824 Anastasia had the distinction of causing the brightest asteroid occultation ever predicted for North America for an asteroid of its size. The asteroid occulted the naked-eye star ζ Ophiuchi over a path stretching from the Los Angeles area to Edmonton, Alberta.

It is believed by Twelver and Alevi Muslims that the Twelve Imams have been foretold in the Hadith of the Twelve Successors. All of the Imams met unnatural deaths, with the exception of the last Imam, who according to Twelver and Alevi belief, is living in occultation.

Observations during two last occultation 18 and 22 December 2010 (P.Baruffetti, G. Tonlorenzi - Massa, G. Bonatti - Carrara, R. Di Luca - Bologna (Italy), C. Schnabel - S. Estebe, J. Rovira - Moja (Spain)) measured a 122.5 km diameter (medium) and an Albedo of 0.0705 compatible with carbonaceous asteroids (C group).

The first X-ray surveys of the sky in the Southern Hemisphere were provided by Skylark launches. It was also used with high precision in September and October 1972 in an effort to locate the optical counterpart of X-ray source GX3+1 by lunar occultation.

During the photometric observations in 2007, mutual eclipse/occultation events suggested that Plutarchos is a synchronous binary asteroid with a minor-planet moon, designated , orbiting it every 40.02 hours. However, neither a diameter estimate for the suspected satellite, nor any follow-up observations have been published since 2007.

In 1971 he discovered a thin atmosphere around Ganymede, a satellite of Jupiter. For this he used ground-based, optical telescope at Kavalur, Tamil Nadu, India. In 1977 he discovered an extended ring system around Uranus using lunar an Occultation technique. The Voyager mission later confirmed his discovery.

Evans and his fellow researchers studied late-type stars showing large starspots, and those subject to flares. They also turned their attention to double stars and multiple stars revealed by lunar occultation. Evans’ major contribution to astronomy was using the angular diameters of stars to calculate their surface brightness.

The Rajʽa doesn't refer exclusively to the theological meaning, but is used in Arabic for other cases such as: remarriage of divorced spouses after a period of waiting, the reappearance of Muhammad al-Mahdi after his occultation, and the reestablishment of an Islamic state in the modern world.

These can result from the dissolution of ammonia in water droplets within water clouds or in the deep water-ammonia ionic ocean. The exact location of the upper two cloud layers is somewhat controversial. Methane clouds were directly detected by Voyager 2 at 1.2–1.3 bar by radio occultation.

In these circumstances, Al-Mahdi gained the Imamate after the death of Hasan al- Askari in 874. In some narrations it is mentioned that Imam Al-Mahdi prayed Salat al-Janazah over his corpse, and then he went into minor occultation from the precaution of the Abbasid authorities.

Measurements of Martian temperature predate the Space Age. However, early instrumentation and techniques of radio astronomy produced crude, differing results. Early flyby probes (Mariner 4) and later orbiters used radio occultation to perform aeronomy. With chemical composition already deduced from spectroscopy, temperature and pressure could then be derived.

Occultation (, ') in Shia Islam refers to a belief that the messianic figure known as the Mahdi, an infallible male descendant of the Islamic Prophet Muhammad, has already been born and subsequently went into hiding, from which he will one day emerge and establish a global Islamic state. The groups that do believe in it differ on the succession of the Imamah, and therefore which individual is in occultation, with the largest Shia branch holding it is Hujjat-Allah al-Mahdi, the twelfth Imam. The Hidden Imam is still considered to be the "Imam of the Era", to hold authority over the community, and to guide and protect individuals and the Shia community.

An occultation of a star by Paris was measured on 17 August 2010, and gave a major and minor occultation axis of kilometers (poor fit). According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide- field Infrared Survey Explorer, Paris measures between 116.26 and 120.45 kilometers in diameter and its surface has an albedo between 0.055 and 0.0626. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0625 and adopts a diameter of 116.26 kilometers from IRAS, based on an absolute magnitude of 8.3. In the catalogs of the three mentioned surveys above, Paris is the 6th, 10th and 11th largest Jupiter trojan, respectively.

Historically, "the Sunnites often applied it [Mahdi] to the four caliphs after the Prophet, who were called al- Khulafa' al-Rashidun al-Mahdiyyun, the rightly guided caliphs.' Sulayman b. Surd called al-Husayn, after his martyrdom, Mahdi b. al-Mahdi".Hussain, Jassim M. Occultation of the Twelfth Imam: A Historical Background.

In this way, a solar eclipse is an occultation of the Sun. Because the Moon is comparatively close to Earth, occultations of individual stars are not visible everywhere on the planet, nor at the same time. Because of the precession of the lunar orbit, each year different stars are occulted.

The Nizari Isma'ili believe that there is no Occultation at all, that the Aga Khan IV is the 49th Imam of the Time. They believe that the Imam's authority is no different from the authority of Ali, the first Imam; he currently provides guidance to Nizaris on worldly and spiritual matters.

Three possible occultation events were observed, suggesting that Parchomenko might be a binary asteroid, having a minor-planet moon as companion. However, no new findings have been made since. In October 2008, Italian amateur astronomer Silvano Casulli measured a similar period of 3.08 hours with an amplitude of 0.27 magnitude ().

Journal of the American Oriental Society, Vol. 106, No. 4 (Oct. - Dec., 1986), pp. 623632. P 624 As a result, Imam Ja'far al- Sādiq’s infallibility is not called into question. The Ithna-‘Asharis continued to follow the Imamate from Mūsā al-Kāẓim’s lineage until their twelfth Imam went into Occultation.

Observing the Earth's atmosphere with radio occultation measurements using the Global Positioning System. J. Geophys. Res. 102:23.429-23.465. This is a relatively new technique (first applied in 1995) for performing atmospheric measurements. It is used as a weather forecasting tool, and could also be harnessed in monitoring climate change.

Lobachevskij covered a 10.4 mag star—a phenomenon known as occultation—in the constellation Sagittarius in June 2007. It was predicted that the event could be seen in the northeastern United States and southeast Canada. The combined light magnitude of the bodies would drop momentarily—for a maximum of 2.2 seconds.

A conjunction of Venus and Jupiter occurred on 1 December 2008, and several hours later both planets separately reached conjunction with the crescent Moon. An occultation of Venus by the Moon was visible from some locations. The three objects appeared close together in the sky from any location on the Earth.

The Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) instrument aboard SCISAT-1 measures the vertical distribution of ozone, nitrogen dioxide, water vapour, and aerosols in the Earth's atmosphere. MAESTRO consists of a UV-VIS-NIR spectrophotometer that measures the 285-1030 nm spectral region.

The Four Deputies (, '), also known as the Gates (, '),Encyclopaedia Iranica (2011). BĀB (1) the Sufara () or the Wukala (), were the four individuals in Twelver Shia Islam who served as messengers between the community and the Hujjat-Allah al-Mahdi, the twelfth and final Imam, upon his going into the Minor Occultation.

Photometric observations of the minor planet in 2011 gave a rotation period of with an amplitude of in magnitude. This result is consistent with previous determinations. Two stellar occultation events involving this asteroid were observed from multiple sites in 2009. The resulting chords matched a smooth elliptical cross-section with dimensions of × .

These books were written with authentic narrators such as Sayyed Ibn Tawus. Muhammad Baqir Majlisi wrote this prayer in Zaad-ul-Maad from Imam Ja'far al-Sadiq. Also, Albazofari, a person who lived in minor occultation, narrated from The Four Deputies of Imam Mahdi that Imam Mahdi said to read the prayer.

The event was visible from Australia and New Zealand. The asteroid has been observed in 3 more stellar occultation events. Photometric observations of this asteroid in 2016 produced lightcurves indicating a rotation period of 9.9 hours with an amplitude variation of 0.18 in magnitude. This result matched previous determinations of the spin rate.

His death was kept secret for a period of 3 years which was called a _ghayba_ or occultation. Eventually, his death was announced and Abd al-Mu'min emerged as the leader the movement and the founder of a new dynasty that lasted until its demise. Abd al-Mu'min eventually conquered Marrakesh in 1147.

1272, # 3264Sonn (2004) p. 209 but, unlike most Shia traditions, Sunni Islam often do not believe the Mahdi has already been born. Sunnis in general reject the Twelver Shi'ite principle of the Mahdi's occultation. Sunnis do, however, rely on traditionally canonical collections of narrations for derivations of the Mahdi's attributes and lineage.

Goldstein, Bruce. SWOOPS/ElectronUser Notes , Jet Propulsion Laboratory Lastly, the radio communications link could be used to search for gravitational wavesThe Gravity Wave Experiment, Astronomy and Astrophysics (through Doppler shifts) and to probe the Sun's atmosphere through radio occultation. No gravitational waves were detected. Total instrument mass was 55 kg (121.3 lb).

159 Complex ābhāsas are compose from simpler ābhāsas, culminating with the whole world.The Himalayan mysticism – R. Nataraj, p. 186The Trika Saivism of Kashmir – M.L. Pandit, p. 188 Paradoxically, even though ābhāsas have the nature of consciousness, they also exist externally on account of being manifested through the occultation power (maya) by Śiva.

Astronomer Michael R. Molnar argues that the "star in the east" refers to an astronomical event with astrological significance in the context of ancient Greek astrology.Weintraub, David A., "Amazingly, astronomy can explain the biblical Star of Bethlehem", Washington Post, December 26, 2014 He suggests a link between the Star of Bethlehem and a double occultation of Jupiter by the moon on March 20 and April 17 of 6 BC in Aries, particularly the second occultation on April 17..For a similar interpretation, see Minnesota Astronomy Review Volume 18 – Fall 2003/2004 Occultations of planets by the moon are quite common, but Firmicus Maternus, an astrologer to Roman Emperor Constantine, wrote that an occultation of Jupiter in Aries was a sign of the birth of a divine king.. He argues that Aries rather than Pisces was the zodiac symbol for Judea, a fact that would affect previous interpretations of astrological material. Molnar's theory was debated by scientists, theologians, and historians during a colloquium on the Star of Bethlehem at the Netherlands’ University of Groningen in October 2014. Harvard astronomer Owen Gingerich supports Molnar's explanation but noted technical questions.

Akhbaris consider themselves to be bounded by the Hadith of the two weighty things, where the Prophet Muhammad instructed his followers to follow the Quran and Ahl al-Bayt. Therefore, even for new events occurring during the Major Occultation, Akhbaris continue to follow traditions of Ahlul Bayt, as per the saying of Imam Muhammad al-Mahdi where he said "As for the new events, which will occur (during my occultation) turn to the narrators of our traditions, because they are my proof to you, while I am the proof of Allah to them"Bahar al-Anwar Vol. 53, p. 181 Akhbari reject fatāwa based on ijtihad, they also reject the permissibility of writing exegesis of the Qur'an without quoting the narrations of the infallible Ahlu l-Bayt.

Another stellar occultation on 19 August 2019 suggested that may be highly oblate in shape, with a projected dimension of km. Another stellar occultation on 8 August 2020, with at least 21 positive detections, resulted in a projected size of km. does not have any known moons orbiting it, thus an accurate mass estimate cannot be made. Based on its size, Brown lists it as nearly certain to be a dwarf planet, however, its low albedo may imply the opposite: dark, mid-sized bodies such as this, less than about 1000 km in diameter and with albedos less than about 0.2, have likely never collapsed into solid bodies, much less differentiated or relaxed into hydrostatic equilibrium, and thus are unlikely to be dwarf planets.

The Four Deputies or Gates ()Encyclopaedia Iranica (2011). BĀB (1), in Twelver Shia Islam, were four individuals who served as intermediaries between the community and the twelfth and final Imam upon his entering the Minor Occultation. The deputies are referred to by the Arabic terms Safir (emissary), Na'ib (deputy) or Wakil (advocate). Twelver tradition holds that four deputies acted in succession to one another from 873–941 CE: # Uthman ibn Sa’id al-Asadi († 873-80) # Abu Jafar Muhammad ibn Uthman ibn Sa’id al-Asadi († 917) # Abul Qasim Husayn ibn Ruh al-Nawbakhti († 938) # Abul Hasan Ali ibn Muhammad al-Samarri († 941) The Major Occultation began following the death of the last deputy and, according to the Shia doctrine, will continue until the return of the Mahdi.

Al-Nawbakhti (, '; , ', meaning "Rebirth" or "Good Luck"), is the Persian surname of several notable figures in Islamic, especially Shia Islamic, theology, philosophy and science. Several variations include Nawbakht, Nūbukht, Nibakht, Naybakht and Ibn Nawbakht. Many members of the Nawbakht family, or clan (Banu Nawbakht), distinguished themselves in the science of the stars and made decisive contributions to the development of the Twelver Shia faith at a time of confusion following the Minor Occultation of the 12th Imam.The clan's theological accomplishments include the formal integration of Mutazila rationalist doctrine into Twelver Shi'ism, explaining the Occultation and defending it against Shia doubters, developing the Imamate doctrine (with emphasis upon such qualities as infallibility) and to lay the groundwork for the authority of the Twelver scholars over their communities.

Most reports about activities of deputies are in Tusi's book al-Ghaybah al-Tusi. According to Abdulaziz Sachedina, it publicly has been pointed to deputies in primary sources such as al-Kulayni and Ibn Babawayh al-Saduq, who has mentioned several people that they had connected with al-Mahdi. Sachedina concludes by reviewing hadiths of Ibn Babawayh that the term "Special Deputies" has been created in explaining the Minor Occultation for the later periods. Sachedina also concludes that no early Twelver sources concerning the occultation, including by authors al-Kulayni, Ibn Babawayh and Shaykh Tusi, confined the names and number of deputies purely to the four that would later be exclusively legitimised; rather, this was later accepted for expediency's sake.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Nestor measures between 107.06 and 112.32 kilometers in diameter and its surface has an albedo between 0.035 and 0.040. The Collaborative Asteroid Lightcurve Link an albedo of and a diameter of kilometers based on an absolute magnitude of 8.99. On 30 June 2006, a dimensional estimate was also obtained from an occultation event by David Gault, when the asteroid eclipsed the star "TYC 6854-00630" (as designated in the Tycho Catalogue) for a duration of 9.52 seconds. Based on this time period, a cross section with the minor and major occultation axes at kilometers was inferred.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Odysseus measures between 114.62 and 130.81 kilometers in diameter and its surface has an albedo between 0.050 and 0.0753. The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0753 and a diameter of 125.64 kilometers based on an absolute magnitude of 7.93. In May 2005, an asteroid occultation gave a best- fit dimension of for the major and minor axis of the occultation ellipse. An estimated mean-diameter of 130, 125 and 114 kilometers measured by Akari, IRAS and WISE, makes Odysseus the 7th, 8th or 10th largest Jupiter Trojan, respectively.

Beatrix (minor planet designation: 83 Beatrix) is a fairly large asteroid orbiting in the inner part of the main asteroid belt. It was discovered by Annibale de Gasparis on April 26, 1865. It was his last asteroid discovery. A diameter of at least was determined from the Beatrician stellar occultation observed on June 15, 1983.

The last occultation by a planet took place on 24 December 1937, when it was occulted by Mercury. It was almost eclipsed by the sun, which occupies a mean, rounded, half of one degree of the sky, on 5 January. Thus the star can be viewed the whole night, crossing the sky, in early July.

She adopted herself Narjis when she came to Arabia.Book of Occultation Biharul Anwar, Allama Muhammad Baqir Majalisi, pp. 11–13 Aside from Shia works, almost nothing is known about the life of this Imam. In the biographies of Mahdi written by Shi'is themselves, it is hard to draw a line between hagiographical and historical works.

Whoever denies me > is not from my (community). The appearance of the Relief depends solely upon > God. Therefore, those who propose a certain time for it are liars. As to the > benefit of my existence in occultation, it is like the benefit of the sun > behind the clouds where the eyes do not see it.

A low probability asteroid occultation of star UCAC2 17967364 with an apparent magnitude of +13.8 was possible on 11 February 2009. Another such event involving a star with an apparent magnitude of +12.9 occurred on 10 April 2014 at about 10:46 Universal Time, visible for observers in the southwest US and western Mexico.

In 1915, Struve received an award from the council of the Russian Astronomical Society, where he was a member from 1893. The award was given for his work “Elaboration of the observations of lunar occultation of the stars during the total lunar eclipse” that was carried within a collaboration between the Kharkov and Pulkovo observatories.

He described the comet of 1718, observations of sunspots and the surface of Venus and of Jupiter, of occultation of the moons of Jupiter, of variable stars, as well as the Northern Lights and the Earth's magnetic field. In 1730 appeared his greatest work He was elected a Fellow of the Royal Society in 1742.

The last occultation by a planet took place on November 17, 1981, when it was occulted by Venus. This is the brightest star that can be principally occulted by an exterior planet between 5000 BC and 5000 AD. However, only Mars can do this, and only rarely; the last time was on September 3, 423.

A reasonably accurate estimate for the diameter of Aldebaran was obtained during the occultation of 22 September 1978. Aldebaran is in conjunction with the Sun around June 1 of each year. With a near-infrared J band magnitude of −2.1, only Betelgeuse (−2.9), R Doradus (−2.6), and Arcturus (−2.2) are brighter at that wavelength.

Communication was lost at 3:02 AM PDT just as Magellan was about to > enter an Earth occultation on orbit 15032. Contact was not re-established. > Tracking operations were continued to 11:00 AM but no signal was seen, and > none was expected. The spacecraft should land on Venus by 1:00 PM PDT > Thursday, October 13, 1994.

These timed observations are taken when the asteroid passes in front of a distant star. The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE albedo of 0.1149 and takes a diameter of 84.61 kilometers based on an absolute magnitude of 8.33, while Josef Ďurech calculates a diameter of by combining lightcurve inversion models with asteroid occultation silhouettes.

Khagol Vishwa (KV) is an organization for amateur astronomers working in Maharashtra, India. It was established on 17 November 1999. The main activity of KV is to conduct observations of astronomical events, like meteor showers, eclipses, occultation, variable stars and generate scientific data for amateur research. Along with scientific studies, KV is also active in science popularization.

27 Piscium is a binary star system in the zodiac constellation of Pisces. It is visible to the naked eye with an apparent visual magnitude of 4.88. Based upon an annual parallax shift of , it is located about 234 light years away. The system is positioned near the ecliptic and so is subject to occultation by the Moon.

22 Tauri is a component of the Asterope double star in the Pleiades open cluster. 22 Tauri is the stars' Flamsteed designation. It is situated near the ecliptic and thus is subject to lunar occultation. The star has an apparent visual magnitude of 6.43, which is near the lower threshold of visibility to the naked eye.

Both Atala and Céluta are American Indian fictional characters.; An occultation of a star by Atala was observed from Japan on 11 March 1994. Subsequent occultations have been observed as recently as 2006. Photometric of this asteroid made in 1981 gave a light curve with a period of 5.282 ± 0.004 hours with a brightness variation of 0.50 in magnitude.

A branch of the Ismāʿīlī known as the Sab'īyah "Seveners" hold that Ismāʿīl's son, Muhammad ibn Ismail, was the seventh and final Ismāʿīlī Imam, who is said to be in the Occultation. However, most scholars believe this group is either extremely small or non-existent today. The Qaramita were the most active branch of the Seveners.

The latter claimed that the ruling Fatimid caliph was the Imām. However, in the Mustaali branch, the Dai came to have a similar but more important task. The term Dāʻī al-Mutlaq () literally means "the absolute or unrestricted missionary". This dai was the only source of the Imām's knowledge after the occultation of al-Qasim in Mustaali thought.

10µ radiometric data collected from Kitt Peak in 1975 gave a diameter estimate of 114 km. Since 1985, a total of three stellar occultations by Antigone have been observed. A favorable occultation of a star on April 11, 1985, was observed from sites near Pueblo, Colorado, allowing a diameter estimate of 113.0 ± 4.2 km to be calculated.

The technique involves a low- Earth orbit satellite receiving a signal from a GPS satellite. The signal has to pass through the atmosphere and gets refracted along the way. The magnitude of the refraction depends on the temperature and water vapor concentration in the atmosphere. GPS Radio occultation amounts to an almost instantaneous depiction of the atmospheric state.

In 1991, an occultation of the star SAO 93228 by Vesta was observed from multiple locations in the eastern United States and Canada. Based on observations from 14 different sites, the best fit to the data was an elliptical profile with dimensions of about × . Dawn confirmed this measurement. Vesta became the first asteroid to have its mass determined.

Ja'far as-Sadiq, the 9th Isma'ili imam who lived in occultation in the era of Abbasids, at the beginning of the Islamic Golden Age. Some suggest that besides Ismailism, the Brethren of Purity also contains elements of Sufism, Mu'tazilism, Nusairism, Rosicrucianism, etc.Brethren of Purity, Nader El-Bizri, an article in Medieval Islamic Civilization, an Encyclopedia, Vol. I, p.

These designations have been used as the rings' names since then. Later they found four additional rings: one between the β and γ rings and three inside the α ring. The former was named the η ring. The latter were dubbed rings 4, 5 and 6—according to the numbering of the occultation events in one paper.

During the photometric observations in February 2009, it was discovered that Seilandfarm is in fact a binary system. Its minor-planet moon has an orbital period of 31.6 hours. Based on mutual eclipse/occultation events, the satellite is thought to be at least 29% the size of Seilandfarm, which translates into a diameter of approximately 2 kilometers or more.

During the photometric observations in March 2012, Brian Warner found evidence of the existence of a minor-planet moon orbiting McAuliffe every 20.86 hours. However, it is only a "possible" synchronous binary system, as no mutual eclipsing/occultation events were observed. Follow-up observations in September and October 2016, did not confirm the binary nature of McAuliffe.

On the sixth day after receiving the letter, Abu al-Hasan Ali ibn Muhammad al-Samarri died (939 AD) and he was buried in Baghdad near the current grave of Sheikh Kulayni. Before his death, they asked him about the next deputy and he responded: "I don't have permission to introduce anyone". Following his death, the Major Occultation began.

Watson asked Prince Gong to name the asteroid. Gong's choice was 瑞華星 (roughly, "Star of China’s Fortune"). Watson used only the first two characters, transliterating them as Juewa according to the conventions of his time (in modern pinyin, it would be transliterated as ruìhuá). Multichord occultation by 139 Juewa, observed 31 August 2013 from N.S.W., Australia.

618 Elfriede is a minor planet orbiting the Sun. On July 24, 2013, it occulted the magnitude 12.8 star 2UCAC 23949304, over parts of Mexico and southwestern United States.Asteroid Occultation - (618) Elfriede Photometric observations of this asteroid collected during 2008 show a rotation period of 14.85 ± 0.01 hours with a brightness variation of 0.12 ± 0.02 magnitude.

It is possibly a mercury-manganese (HgMn) star, but abundances of other metals are unexpectedly low. Beta Scorpii is 1.01 degree from the ecliptic and can be occulted by the Moon and, very rarely, by planets. On December 9, 1906, it was occulted by Venus. The last occultation by a planet took place on 13 May 1971, by Jupiter.

Rex King rejected all claimants to the Guardianship after Shoghi Effendi including Remey. He claimed that he, Rex King, was a "regent" pending the emergence of the second Guardian who was in "occultation". His group called themselves the Orthodox Baháʼí Faith under the Regency. King died in 1977 and appointed four of his family as the council of regents.

The symmetry of the secondary occultations and multiple observations of the event in various locations helped reconstruct not only the shape and size of the object, but also the thickness, orientation, and location of the ring planes. The relatively consistent ring properties inferred from several secondary occultation observations discredit alternative explanations for these features, such as cometary-like outgassing.

In Kavalur, the one-metre Zeiss telescope was installed in 1972, and the very next month, during an occultation event, scientists discovered a trace of atmosphere on Ganymede, the largest satellite of Jupiter. Five years later the same telescope discovered the rings of Uranus. -- Indian Astronomy : From Jantar-Mantar to Kavalur, Department of Science and Technology, Government of India.

The observation demonstrated conclusively that Mercury orbited around the Sun. A rare event in astronomy is the passage of one planet in front of another (occultation), as seen from Earth. Mercury and Venus occult each other every few centuries, and the event of May 28, 1737 is the only one historically observed, having been seen by John Bevis at the Royal Greenwich Observatory.

Hekate was the 100th asteroid to be discovered, by J. C. Watson (his fourth discovery) on July 11, 1868. It is named after Hecate, the goddess of witchcraft in Greek mythology, but its name also commemorates it as the hundredth asteroid, as hekaton is Greek for 'hundred'. A Hekatean occultation of a star was observed on July 14, 2003, from New Zealand.

Julia (minor planet designation: 89 Julia) is a large main-belt asteroid that was discovered by French astronomer Édouard Stephan on August 6, 1866. This was first of his two asteroid discoveries; the other was 91 Aegina. 89 Julia is believed to be named after Saint Julia of Corsica. A stellar occultation by Julia was observed on December 20, 1985.

1728 and albedo of 0.03. The light curve collected over 6 nights from 2/16/2002 to 3/10/2002 confirmed the rotational period to be 19.718h. Data from 2001 shows a diameter of 45.37 km. An occultation by the asteroid was observed on December 10, 2017, showing the asteroid to be highly elongated, with dimensions of roughly 24 x 52 km.

This suggests that the asteroid underwent differentiation by melting, creating a surface of basalt rock. The mass of Thetis has been calculated from perturbations by 4 Vesta and 11 Parthenope. In 2007, Baer and Chesley calculated Thetis to have a mass of 1.2 kg with a density of 3.21 g/cm³. One Thetidian stellar occultation was observed from Oregon in 1999.

After a brief research position at Harvard, Taylor went to the University of Massachusetts Amherst, eventually becoming Professor of Astronomy and Associate Director of the Five College Radio Astronomy Observatory. Taylor's thesis work was on lunar occultation measurements. About the time he completed his Ph.D., Jocelyn Bell (who is also a Quaker) discovered the first radio pulsars with a telescope near Cambridge, England.

Eclipses in the light curve of QR Andromedae are not symmetrical: the ingress is more gradual than the egress. The secondary minimum is variable in occurring phase and depth, meaning that the occultation of the secondary star happens behind a variable part of the disk. Out of the eclipses, light flickering can be clearly seen, and in some observations a periodicity arise.

The network of agents (Wikalah) was established during the sixth Imam, Ja'far al-Sadiq. It peaked in the time of the eleventh Imam, Hasan al-Askari. The network of agents was especially important during the minor occultation, because Imam Mahdi only contacted his followers through the agents. The function of this system is shown in letters of instruction of the Al-Hadi.

The photometric observations by William Ryan and collaborators also showed that Volkonskaya is an asynchronous binary asteroid with a minor- planet moon orbiting it every 24 hours at an estimated average distance of . The discovery was announced in December 2005. The mutual occultation events suggest the presence of a satellite with an estimated diameter or 40% the size of its primary.

Al-Tirmidhi attributes to Ibn Abbas the tradition that Muhammad acquired the sword on the day of Badr, after he had seen it in a dream concerning the day of Uhud. According to the Twelver Shia, the Dhū al-Fiqār is currently in the possession of the Imam in occultation Hujjat-Allah al-Mahdi, alongside other religious relics, such as the al-Jafr.

VBSDC searched for dust, inferring meteoroid collision rates and any invisible rings. REX performed active and passive radio science. The communications dish on Earth measured the disappearance and reappearance of the radio occultation signal as the probe flew by behind Pluto. The results resolved Pluto's diameter (by their timing) and atmospheric density and composition (by their weakening and strengthening pattern).

Born in Ferrara, for 21 years he was professor of astronomy at the University of Bologna, and in 1500 he also lectured in mathematics at Rome. He was notable as a Platonist astronomer, and in 1496 he taught Nicolaus Copernicus astronomy. He was also an astrologer. At Bologna, Novara was assisted by Copernicus, with whom he observed a lunar occultation of Aldebaran.

An artist's rendering of Chariklo with its rings Artist's impression of the surface of Chariklo and its rings. A stellar occultation in 2013 revealed that Chariklo has two rings with radii 396 and 405 km and widths of about 7 km and 3.5 km respectively. The rings are approximately 9 km apart. This makes Chariklo the smallest known object to have rings.

During the minor occultation, al-Mahdi connected with Shiites by his Four Deputies. When believers faced difficulty, they would write their concerns and send them to his deputy. The deputy would receive the decision of the Imam, endorse it with his seal and signature, and return it to the concerned parties. The deputies also collected zakat and khums on his behalf.

Mahdi of Sunni and Mahdi of Shia are different. Sunni Muslims do not consider the son of Hasan al-Askari to be the Mahdi nor to be in occultation. However, they do believe that the Mahdi will come from Muhammad's family.al-Mahdi Sunnis believe that the Mahdi has not yet been born, and therefore his true identity is known only to Allah.

He participated and won awards in scores of art exhibitions across the country. His award winning painting Occultation went on tour in the traveling section of the California Water Color Society's Annual Exhibition of 1962. His abstract work Northward was requested by the Long Beach Museum of Art in 1957 and remains in the museum's permanent collection as Abstract Expressionism.

The research areas of ASIAA range from the Solar System to star formation to galaxies and cosmology. ASIAA has either led or co-led the construction and operation of several telescopes, including the AMiBA Telescope to study the cosmic microwave background radiation (also known as "Lee Array"), the Taiwanese-American Occultation Survey, the Submillimeter Array and many other research projects.

Solar eclipses on Jupiter occur when any of the natural satellites of Jupiter pass in front of the Sun as seen from the planet Jupiter. For bodies which appear smaller in angular diameter than the Sun, the proper term would be a transit. For bodies which are larger than the apparent size of the Sun, the proper term would be an occultation.

Over the years, Iowa State researchers used the Fick Observatory for a wide variety of studies, including stellar radial velocity observations, studies of ring galaxy collisions, and lunar occultation studies. In 2015, the Erwin W. Fick Observatory closed. It was the last astronomical research observatory operated by a college or university at a dark-sky site in the state of Iowa.

It is specified as a spectral standard for that type. The angular diameter of the star measured from a lunar occultation is , which, at its estimated distance, equates to a physical radius of about 31 times the radius of the Sun. It is radiating 137 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,487 K.

This was first performed by Giovanni Domenico Cassini in 1672. The early parallax measurements were hampered by the quality of the instruments. The only occultation of Mars by Venus observed was that of 13 October 1590, seen by Michael Maestlin at Heidelberg. In 1610, Mars was viewed by Italian astronomer Galileo Galilei, who was first to see it via telescope.

One of its observations was of Comet Encke. The Sheepshanks was used to observe the moon occulting stars in 1905. Some of the stars that were observed include Bradley 687, 130 Tauri, and 26 Geminorum- among others. In addition to the occultation of stars by the Moon, the Sheepshanks equatorial is also reported to have been used to observe the moons of Jupiter.

FASTT was also used to help NASA's SOFIA Airborne Observatory correctly locate, track and image a rare Pluto occultation. FASTT is located southwest of the primary complex. Attached to its large "hut" is the building housing NOFS' electronics and electrical engineering laboratories and clean rooms, where most of the advanced camera electronics, cryogenics and telescope control drives are developed and made.

In between is the small faint emission nebula IC 444 around the 7th magnitude 12 Geminorum. η Geminorum is 0.9 degree south of the ecliptic, so it can be occulted by the Moon and, rarely, by planets. The last occultation by a planet took place on July 27, 1910, by Venus, and the next to last on July 11, 1837, by Mercury.

Epsilon Geminorum lies near the ecliptic, so it can be occulted by the Moon or a planet. Such an occultation took place on April 8, 1976 by Mars, which allowed the oblateness of the planet's outer atmosphere to be measured. Epsilon Geminorum was occulted by Mercury on June 10, 1940, and on September 3, 2015 it was occulted by the asteroid Iphigenia.

This does not mean that jivatman is limited, it just appears so on account of ignorance.The Pratyabhijna Philosophy – G.V. Tagare, p. 32 Jivatman is not created or born, but rather has the same status as Śiva, performing on a small scale the same actions that Śiva performs on a universal scale – creation, maintenance, dissolution, occultation and grace.The Pratyabhijna Philosophy – G.V. Tagare, p.

The camera is fitted with a double filter wheel, allowing 12 different filters and one clear position. The telescope condominium is a joint venture between the University of Liège, Belgium, and Geneva Observatory, Switzerland, and among other tasks, it specializes in searching for comets and exoplanets. In November 2010, it was one of the few telescopes that observed a stellar occultation of the planetary body Eris, revealing that it may be smaller than Pluto, and it helped observe a stellar occultation by Makemake, when it passed in front of the star NOMAD 1181-0235723. The observations of this event showed it lacked a significant atmosphere. A team of astronomers headed by Michaël Gillon, of the Institut d’Astrophysique et Géophysique at the University of Liège in Belgium, used the telescope to observe the ultracool dwarf star 2MASS J23062928-0502285, now also known as .

The idea of occultation in Islam has its origin in the Kaysanites whose members had considered Muhammad ibn al-Hanafiyyah the Mahdi. When his son, Abu Hashem died childless some of the Kaysanites again maintained that he was the Qa'im, who is in concealment in the Razwa mountain. The Waqifi (Sevener) cessationists were another group who maintained that the Imamate was ceased with Musa al- Kadhim the seventh Shia Imam and refused to accept his death as they believed he had gone into occultation. Finally the companions of Hasan al-Askari, the eleventh Imam, also believed he had a son whose birth, like that of the prophet Moses was concealed, and due to the belief that he was the promised Mahdi; Al-Mutamid ordered the house of the Imam to be investigated, and to find out if the Imam had left a son.

The next occultation of Mercury by Venus will be on December 3, 2133. The difficulties inherent in observing Mercury mean that it has been far less studied than the other planets. In 1800, Johann Schröter made observations of surface features, claiming to have observed mountains. Friedrich Bessel used Schröter's drawings to erroneously estimate the rotation period as 24 hours and an axial tilt of 70°.

The spectra of this asteroid displays a feature at a wavelength of 3 μm, indicating the presence of hydrated minerals on the surface. The near infrared spectrum is reddish and shows no spectral absorption features. Potential analogs of this spectrum include enstatite chondrites and nickel- iron meteorites. A three-chord occultation plot of the asteroid 77 Frigga, observed 2018 April 11th from eastern Australia.

Differential bending of light was measured to be consistent with general relativity. Regulus was occulted by the asteroid 163 Erigone in the early morning of March 20, 2014. The center of the shadow path passed through New York and eastern Ontario, but no one is known to have seen it, due to cloud cover. The International Occultation Timing Association recorded no observations at all.

In the SMASS taxonomy, Tesla is a dark C-type asteroid. According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Tesla measures 24.37 kilometers in diameter and its surface has a low albedo of 0.050, in correspondence with its carbonaceous composition. A larger diameter estimate of 29 kilometers was obtained in 2008, from an asteroid occultation.

Vala (minor planet designation: 131 Vala) is an inner main-belt asteroid. It was discovered by C. H. F. Peters on 24 May 1873, and named after Völva, a prophetess in Norse mythology. One observation of an occultation of a star by Vala is from Italy (26 May 2002). 10-μm radiometric data collected from Kitt Peak in 1975 gave a diameter estimate of 34 km.

This is to facilitate direct follow-up transit observations of TESS candidate planets (particularly those in fields from which TESS has moved on). It can also enable the observation of occultation events and other transient targets-of- opportunity. During commissioning, observations made by the MINERVA-Australis array contributed to the discovery of 13 new exoplanets, working in collaboration with researchers at institutions across the globe.

It lies near the ecliptic and thus is subject to occultation by the Moon. One such event was observed September 3, 1991. This system forms a wide double star with an angular separation of along a position angle of 230°, as of 1991. The brighter star, component A, has an apparent magnitude of 4.99 while the fainter secondary, component B, is of magnitude 9.09.

The composition of the Uranian atmosphere is different from that of Uranus as a whole, consisting mainly of molecular hydrogen and helium. The helium molar fraction, i.e. the number of helium atoms per molecule of hydrogen/helium, was determined from the analysis of Voyager 2 far infrared and radio occultation observations. The currently accepted value is in the upper troposphere, which corresponds to a mass fraction .

Atmospheric radio occultation relies on the detection of a change in a radio signal as it passes through a planet's atmosphere, i.e. as it is occulted by the atmosphere. When electromagnetic radiation passes through the atmosphere, it is refracted (or bent). The magnitude of the refraction depends on the gradient of refractivity normal to the path, which in turn depends on the density gradient.

During Warner's photometric observations in 2012, it was revealed that Smetana is a synchronous binary asteroid with an orbiting minor- planet moon. The satellite, designated , orbits its primary every 22.43 hours and measures approximately 0.63 kilometers in diameter. However the binary status of Smetana has not yet been confirmed unambiguously, since observations in 2016 could not clearly detect any mutual occultation and eclipsing events.

On 2 November 2014, Yoichi occulted 8.4 magnitude star in the constellation Cetus, causing a magnitude drop from 8.4 to 14.1 during 2.8 seconds. The occultation was visible over Southern Japan, Eastern China, as well as from Southern California to North Florida. The asteroid's 23-kilometer-wide shadow had a speed of approximately . An approximate diameter of 20 kilometers was assumed for the asteroid.

4672 Takuboku, provisional designation , is a background asteroid from the outer regions of the asteroid belt, approximately in diameter. It was discovered on 17 April 1988, by Japanese astronomers Seiji Ueda and Hiroshi Kaneda at the Kushiro Observatory on Hokkaido, Japan. The asteroid was named after the Japanese poet Takuboku Ishikawa. In 2005, measurement of the body's occultation ellipse also gave 35.0 × 35.0 kilometers.

The equatorial mount and mechanical clock drive were made by George N. Saegmuller. This telescope was used for scientific work such as lunar occultation timings to make a more precise determination of the orbit of the Moon. Instruments such as a filar micrometer could be attached to the telescope. Another telescope, a meridian circle instrument, also made by Saegmuller, was used for observations related to timekeeping.

Challenging Minisatellite Payload (CHAMP) was a German satellite launched July 15, 2000 from Plesetsk, Russia and was used for atmospheric and ionospheric research, as well as other geoscientific applications, such as GPS radio occultation. CHAMP was managed by GeoForschungsZentrum (GFZ) Potsdam (GFZ). The spacecraft is the first application of Astrium's "Flexbus" platform; GRACE was the second. A heavily modified version flew as the GOCE mission.

Such occultations occur when the Moon's ascending node is near the autumnal equinox. A series of 49 occultations occurred starting on 29 January 2015 and ending at 3 September 2018. Each event was visible from points in the northern hemisphere or close to the equator; people in e.g. Australia or South Africa can never observe an Aldebaran occultation since it is too far south of the ecliptic.

The last were the marja'iyya (see Marja).Baqir Al-Sadr, Al-Islam yaqud al-hayat, Qum, 1979, p.24 While the two functions of khilafa and shahada (witness; supervision) were united during the times of the Prophets, they diverged during the occultation so that khilafa returned to the people (umma) and shahada to the scholars.Faleh A Jabar, The Shi'ite Movement in Iraq, London: Saqi Books, 2003, p.

As a result of the aforementioned 1977 occultation, a small moon around Hebe was reported by Paul D. Maley.W. R. Johnston Other reports of Asteroid/TNO Companions It was nicknamed "Jebe" (see heebie-jeebies). This was the first modern-day suggestion that asteroids have satellites. It was 17 years later when the first asteroid moon was formally discovered (Dactyl, the satellite of 243 Ida).

Photometric observations of this asteroid at the Organ Mesa Observatory in Las Cruces, New Mexico in 2011 gave a light curve with a period of 37.394 ± 0.002 hours and a brightness variation of 0.10 ± 0.01 in magnitude. The curve is asymmetrical with four uneven minima and maxima. Occultation data from October 9, 2006 using 15 chords shows the asteroid is about 130 km in diameter.

The main concepts of the book are the lifestyle of Imams and their aims in life. The period of 250 years is applied to the tenth lunar Hijri year (631 CE) until the Minor Occultation (874 CE). According to this book, Mohammad the prophet and the twelve Imams apparently had various methodologies in their lifestyles, but in whole they tried to reach one aim.

Jamkaran in Iran, supposed site of a historical appearance of Muhammad al-Mahdi In the tradition of Twelver Shia Islam, the twelfth and final Imam, Muhammad al-Mahdi, who is also considered by Twelver Shia to be the prophesied redeemer of Islam known as the Mahdi, went into ghaybah ("occultation") in 873. However, this belief has long been criticized by Sunni scholars who "often speculate that the twelfth Imam never existed, but was a myth designed to keep the Shia cause alive."The Routledge Handbook of Religion and Security, by Chris Seiple, Dennis R. Hoover, Pauletta Otis, 2012, page 60 Meanwhile, western scholars have also cast doubt upon the existence of an occulted Imam. According to Robert Gleave, the occultation of the 12th Imam "became subsequent orthodox doctrine" after none of the competing theories that sought to explain the succession to a childless 11th Imam "seemed satisfactory".

Artemis (minor planet designation: 105 Artemis) is a main-belt asteroid that was discovered by J. C. Watson on September 16, 1868, at Ann Arbor, Michigan. It was named after Artemis, the goddess of the hunt, Moon, and crossways in Greek Mythology. Several Artemidian stellar occultations have been reported. An occultation of the star HD 197999 was observed in 1982, which gave an estimated chord length of 110 km.

Observed minor planet occultation events, version of 2005 July 26 During 2000, 88 Thisbe was observed by radar from the Arecibo Observatory. The return signal matched an effective diameter of 207 ± 22 km. This is consistent with the asteroid dimensions computed through other means. Photometric observations of this asteroid during 1977 gave a light curve with a period of 6.0422 ± 0.006 hours and a brightness variation of 0.19 in magnitude.

According to Tayyibi Isma'ilism, during the Occultation of the twenty-first imam, at-Tayyib Abu'l-Qasim, a Da'i al-Mutlaq "Unrestricted Missionary", maintains contact with him.'Aqeedat ul-Muwahhedeen wa Muzehato Maraatib Ahl id-Deen: 8th Da’i-e- Mutlaq Saiyedna Husain bin Saiyedna Ali bin Mohammad al-Waleed (d. 667 AH/1269 AD) The several branches of the Musta'li Shia differ on who the current Da'i al-Mutlaq is.

During Brian Warner's photometric observations, two possible mutual eclipsing/occultation events were observed, indicating that Karayusuf is a binary asteroid with a satellite in its orbit. The data, however, was insufficient to calculate a rotation period. In 2010 and in 2014, when observing conditions had a nearly identical phase angle, no evidence of an orbiting minor-planet moon was found. The results of the 2018-observation have not yet been published.

However, this short rotation period was most likely an alias due to a bias for shorter and more easily discernable shorter periods. is highly oblate, and Ortiz et al. suggest a longer rotation period estimate of 56.1 h. An occultation of a 15.3 magnitude star by on 28 January 2018 over Europe suggests that it has highly oblate shape with dimensions of × and a projected axial ratio of a/c=1.18.

Tycho finds her in a telephone box. She refuses to tell him what has happened, and so Tycho gives her some money and leaves her be. Tycho returns home, where he uses the excuse of wanting to see the occultation of two of Jupiter's moons to get out of going to his sister's for a party that evening. After they have left, he calls Dido, but Angela has not returned yet.

In Shia Islam it is assumed that the Imams inherited their teachings from Prophet Muhammad. The Imams therefore, are considered the first authorities of Qur'anic interpretation. Next come the disciples of the Imams who were mainly transmitters of hadith. The first formative stage of Shia tafsir is therefore referred to the period of the living Imams, including that of the four representatives of the twelfth imam during his lesser occultation.

In the 1990s, observations from Earth were made of the occultation of stars by Triton's limb. These observations indicated the presence of a denser atmosphere than was inferred from Voyager 2 data. The surface pressure in the late 1990s is thought to have increased to at least 19 μbar or, possibly, even to 40 μbar. Other observations have shown an increase in temperature by 5% from 1989 to 1998.

Retrieved on 16 January 2012.Other Collections, by Dr. Muhsin M R Alidina . al-huda.al-khoei.org. Retrieved on 16 January 2012. The Twelver Shia believe that Al-Jamia is currently in the possession of the 12th Imam Muhammad al-Mahdi, after he inherited it from his predecessors. But according to them, the Imam went into major occultation, and will not come in contact with the world until the end of times.

During the photometric observations by Donald Pray, Petr Pravec and collaborators in March 2006, it was revealed that Tatianina is a synchronous binary asteroid with a minor-planet moon orbiting it every 21.67 hours at an estimated average distance of . The discovery was announced on 11 April 2006. The mutual occultation events suggest the presence of a satellite with an estimated diameter of meters or 19% the size of its primary.

A conjunction of the Moon and Mars took place on 24 December 2007, very close to the time of the full Moon and at the time when Mars was at opposition to the Sun. Mars and the full Moon appeared close together in the sky worldwide, with an occultation of Mars occurring for observers in some far northern locations. A similar conjunction took place on 21 May 2016.

The 29-hour rotation period is unusually long for an asteroid more than 150 km in diameter. Its spectral class is intermediate between the C-type and P-type asteroids. 10μ radiometric data collected from Kitt Peak in 1975 gave a diameter estimate of 255 km. An occultation of Bamberga was observed on 8 December 1987, and gave a diameter of about 228 km, in agreement with IRAS results.

Amateur astronomers continue to make scientific contributions to the field of astronomy and it is one of the few scientific disciplines where amateurs can still make significant contributions. Amateurs can make occultation measurements that are used to refine the orbits of minor planets. They can also discover comets, and perform regular observations of variable stars. Improvements in digital technology have allowed amateurs to make impressive advances in the field of astrophotography.

Demands for Grants, 2017–2018. India's Department of Space. From 2016 to 2017, ISRO collaborated with JAXA to study the Venus atmosphere using signals from the Akatsuki in a radio occultation experiment. The three broad research areas of interest for this mission include surface/subsurface features and re-surfacing processes; second: study the atmospheric chemistry, dynamics and compositional variations, and third: study the atmospheric interaction with solar radiation and solar wind.

Since 1988 there have been 8 reported stellar occultations by Juewa. From the occultation on 31 August 2013 the best fit ellipse measures 148.3+/-4.3 km x 142.3 +/- 15.6 km. 13-cm radar observations of this asteroid from the Arecibo Observatory between 1980 and 1985 were used to produce a diameter estimate of 172 km. Based upon radar data, the near surface solid density of the asteroid is 1.5.

Omicron Piscium (ο Piscium, abbreviated Omi Psc, ο Psc) is a binary star in the constellation of Pisces. It is visible to the naked eye, having an apparent visual magnitude of 4.27. Based upon an annual parallax shift of 11.67 mas as seen from the Earth, the system is located roughly 280 light- years from the Sun. It is positioned near the ecliptic, so is subject to occultation by the Moon.

A shape model of Nausikaa has been constructed, also based on the lightcurve data. It indicates a roughly cut, but not very elongated body. In 1998 an occultation of a star by the asteroid was observed from the United States. In 1988 a search for satellites or dust orbiting this asteroid was performed using the UH88 telescope at the Mauna Kea Observatories, but the effort came up empty.

Ayatollah Naini was active both in Iran's Constitutional Revolution and in Iraqi Politics. As a politician his principal view with regard to form of government is very clear. He suggested the form of government by an infallible ruler fully responsible to the will of God, which might be able to safeguard the interests of people. Such type of ruling is not possible in the era of major occultation of Imam Mahdi.

It is 5.39 degrees north of the ecliptic, so it can be occulted by the Moon. Such occultations occur when the Moon's ascending node is near the vernal equinox, as was the case in 2007. Most occultations are visible only in the Southern Hemisphere, because the star is at the northern edge of the lunar occultation zone. Rarely, it may be occulted as far north as southern California.

RASNZ coordinates a number of sections (groups of people who share a common interest) including the Occultation, Education and Variable Star sections. The RASNZ holds an annual conference, generally hosted by one of the affiliated societies. The conference is open to non-members. A wide range of papers are presented during the conference and often symposiums related to the RASNZ's sections are held in conjunction with the conference.

Under his directorship, the study of photoelectric photometry was introduced and the study of comets, variable stars, lunar occultation, solar activity and study of motion of clusters was undertaken. It also participated in the solar and seismological observations as part of the International Geophysical Year (1957-58). A K Das was Director of the Observatory in 1960 for a very short time after his retirement as Director of Kodaikanal Observatory.

Panca-Kritya is a general practice which underlies all the other practices. An essential feature of Kashmir Shaivism is the concept of activity inside the ultimate consciousness. Śiva acts, and his most important actions are five in number: creation, maintenance, dissolution, occultation and grace. But the limited beings are identical to Śiva, as nothing but Śiva exists, so, they too have the same five actions, on a limited scale.

Henry Corbin in contrast believed that the question of historicity is irrelevant admitting that the idea of the hidden Imam was shaped by the person of twelfth and considering the extensive body of literature about him, saw the birth and his occultation as archetypal and symbolic, describing it as "sacred history". In his History of Islamic Philosophy He writes: "The simultaneity of these (birth and occultation) is rich in meanings from the mystical point of view… here above all, our approach should be that of the phenomenological: we must discover the aims of Shi’ite awareness...". There was a hadith that was already present in orthodox Sunni collections wherein Muhammad declares that he will be followed by twelve caliphs (alternative versions have qayyims) from his descendants all from his tribe, the Quraysh. The hadith appears in both Bukhari (as amirs Bab al- istakhlaf, 7062) and Muslim (as "caliphs", Bab al-nas taba l-Quraysh, 4667).

However, there was uncertainty over whether a spacecraft could survive passage through the asteroid belt, where micrometeoroids could cause it physical damage, or the intense Jovian magnetosphere, where charged particles could harm sensitive electronics. To resolve these questions before sending the more ambitious Voyager missions, NASA and the Ames Research Center launched a pair of twin probes, Pioneer 10 and Pioneer 11 on March 3, 1972 and April 6, 1973, respectively, on the first unmanned mission to the outer Solar System. Pioneer 10 became the first spacecraft to reach the Jupiter system on December 3, 1973. It passed within of Io. During Pioneer 10's fly-by of Io, the spacecraft performed a radio occultation experiment by transmitting an S-band signal as Io passed between it and Earth. A slight attenuation of the signal before and after the occultation showed that Io had an ionosphere, suggesting the presence of a thin atmosphere with a pressure of 1.0 bar, though the composition was not determined.

According to Sharif al-Murtaza the twelfth Imam used to appear before his adherents at the beginning of his Occultation concealing himself only from his enemies; only later, when danger to his life increased, did he have to hide from both followers and adversaries, as there are numerous stories of the Hidden Imam "manifesting himself to prominent members of the Ulama" When Jabir ibn Abd Allah asked the prophet about the benefits of a hidden Imam, the prophet replied that the people would benefit from his Walayah (Twelver doctrine) as they benefit from the sun when it is covered by the clouds. According to Sachedina, in every age there is an Imam whether be apparent or hidden. As for Mahdi because of the dangers which threatening his life, he is concealed by God's order. Al-Numani states two reasons for the Occultation: the believers being evaluated by God for their assiduity to their hidden Imam and the hidden Imam not undergoing the Bay'h of the cruel leaders.

The text of Ziyarat Ale Yasin with its voice sibtayn.com Retrieved 29 January 2018 Abu Jafar Muhammad b. ‘Abdullah al Himyary al Qommi as the narrator of this Ziyarat was lived in the terminal period of the minor occultation and likewise many of his letters to the twelfth Imam of Shia (Mahdi) have been narrated, according to source(s). One Tawqi which contains the Ziyarat Ale Yasin, can be considered as one of those letters.

Minerva (minor planet designation: 93 Minerva) is a large trinary main-belt asteroid. It is a C-type asteroid, meaning that it has a dark surface and possibly a primitive carbonaceous composition. It was discovered by J. C. Watson on 24 August 1867, and named after Minerva, the Roman equivalent of Athena, goddess of wisdom. An occultation of a star by Minerva was observed in France, Spain and the United States on 22 November 1982.

It is named after one of the two Galateas in Greek mythology. A stellar occultation by Galatea was observed on September 8, 1987. The name Galatea has also been given to one of Neptune's satellites. Photometric observations of this asteroid made during 2008 at the Organ Mesa Observatory in Las Cruces, New Mexico gave a light curve with a period of 17.270 ± 0.002 hours and a brightness variation of 0.08 ± 0.01 in magnitude.

Twice during the orbital cycles of Jupiter and Saturn, the equatorial (and satellite) planes of those planets are aligned with Earth's orbital plane, resulting in a series of mutual occultations and eclipses between the moons of these giant planets. The terms eclipse, occultation, and transit are also used to describe these events. A satellite of Jupiter (for example) may be eclipsed (i.e. made dimmer because it moves into Jupiter's shadow), occulted (i.e.

Psi Virginis (ψ Vir, ψ Virginis) is a suspected binary star system in the zodiac constellation of Virgo. It can be seen with the naked eye and has an apparent visual magnitude of +4.80. Based upon the annual parallax shift of 5.99 milliarcseconds, the distance to this star is roughly 540 light years. The angular size of Psi Virginis was measured on December 26, 1975 during an occultation by the Moon, yielding the estimate .

Lunar occultation In 1999, Wieth-Knudsen's widow, Inger Wieth-Knudsen (1914–2004), presented the building as a gift to the Danish Astronomical Society. The observatory holds a 16-inch computer-controlled telescope. On the observatory grounds there are two radio telescopes and a series of platforms for smaller telescopes, including a solar telescope. The public is welcome to free star-gazing events held on the second and the last Saturdays of every month.

Alcock was previously the Reese W. Flower Professor of Astronomy at the University of Pennsylvania. His primary research interests are massive compact halo objects, comets and asteroids. He is the principal investigator for the Taiwan American Occultation Survey, a project aimed at taking a census of the Solar System's population of Kuiper Belt objects (objects located beyond the orbit of Neptune). In 2001, Alcock was elected to the United States National Academy of Sciences.

Since 1980, several rotational lightcurves of Alphonsina have been obtained from photometric observations with rotation periods between 7.876 and 7.92 hours (). The best-rated lightcurve by Alan Harris and James Whitney Young gave a period of 7.880 hours. The consolidated brightness amplitude is between 0.11 and 0.57 magnitude. In 2011, two modeled lightcurves using data from the Uppsala Asteroid Photometric Catalogue (UAPC) and from asteroidal occultation silhouettes gave a concurring period 7.87754 hours.

Observations performed at the Palmer Divide Observatory in Colorado Springs, Colorado during 2007 produced a light curve with a period of 13.120 ± 0.002 hours and a brightness range of 0.21 ± 0.02 in magnitude. Previous measurements from 2000 gave 13.14 and 5.510 hour estimates for the period. Based upon its spectrum, it is classified as an S-type asteroid. An occultation of a star by Maria was observed from Manitoba, Canada, on June 10, 1997.

In 1880s, Fazl Allah was drawn into politics in response to the Qajar government's increasing business concession to foreign businessmen. Drawing upon the views of his mentor, Shirazi, he argued that during the period of Occultation when government and religion have become separate, running the country has to be a shared responsibility of the government and clerics so as to prevent unIslamic decisions by the rulers. This thesis justified the clerics active involvement in politics.

Light curves can be periodic, as in the case of eclipsing binaries, Cepheid variables, other periodic variables, and transiting extrasolar planets, or aperiodic, like the light curve of a nova, a cataclysmic variable star, a supernova or a microlensing event or binary as observed during occultation events. The study of the light curve, together with other observations, can yield considerable information about the physical process that produces it or constrain the physical theories about it.

161 Athor is an M-type Main belt asteroid that was discovered by James Craig Watson on April 19, 1876, at the Detroit Observatory and named after Hathor, an Egyptian fertility goddess. An occultation by Athor was observed, on October 15, 2002, resulting in an estimated diameter of . Photometric observations of the minor planet in 2010 gave a rotation period of with an amplitude of in magnitude. This result is consistent with previous determinations.

When an exoplanet passes in front of the host star, a small dip in the light received from the star may be observed. The transit method is currently the most successful and responsive method for detecting exoplanets. This effect, also known as occultation, is proportional to the square of the planet's radius. If a planet and a moon passed in front of a host star, both objects should produce a dip in the observed light.

A two chord stellar occultation by the asteroid observed in 2004 gave an approximate diameter of 50 km. French amateur astronomer Pierre Antonini obtained a lightcurve of Dufour from photometric observations taken during April 2010. Lightcurve analysis gave a well-defined rotation period of hours with an amplitude of 0.31 in magnitude (). In August 2013, photometric observations at the Palomar Transient Factory, California, gave a similar period of hours with a brightness variation of 0.35 ().

During the photometric observation in 2007, it was also revealed, that Pogson is an asynchronous binary system with a minor-planet moon in its orbit. The mutual eclipse and occultation events showed that the companion, provisionally designated , orbits its primary every 24.24 hours. Based on a secondary-to-primary diameter ratio of 0.32 or larger, Johnston's archive estimates a diameter of 2.52 kilometers for the satellite, separated by 8 kilometers from its primary.

The planet was discovered by observing the amount of stellar flux reaching the Earth. The existence of the planet was confirmed by also observing the reflected starlight from the planet, the shape of the star due to gravitational tug from the planet and radial velocity method. Finally, part of the planet was found transiting the parent star with secondary occultation also being detected. It is the first planet detected using Einstein's special relativity.

Henry Lawson (1774–1855) was an English astronomer, member of the Royal Astronomical Society, the Royal Society, and the British Meteorological Society, as well as an inventor, designer, science educator, and philanthropist. He observed an occultation of Saturn on 8 May 1832, Johann Gottfried Galle's first comet in December 1839 and January 1840, and recorded the falling stars of 12–13 November 1841. He claimed to have been related to Catherine Parr.

It is located near the ecliptic and hence is subject to occasional occultation by the Moon. This is an F-type main sequence star with a stellar classification of F2 Vw, where the 'w' indicates weak absorption lines in the spectrum. The star is around 582 million years old with a projected rotational velocity of 29 km/s. It has 1.5 times the mass of the Sun and 1.6 times the Sun's radius.

Lightcurve Inversion model DAMIT 1806 and occultation chords from two observations of 2010 and 2014. The orbit of Psyche between Mars and Jupiter is near-circular The first size estimate of Psyche came from IRAS thermal infrared emission observations. They showed that it had a diameter of about 253 km, although it was likely an overestimate as Psyche was viewed pole-on at that time. Light curve analysis indicates Psyche appears somewhat irregular in shape.

Haumea's 3.9155-hour rotation within its discovered ring A stellar occultation observed on 21 January 2017 and described in an 11 October 2017 Nature article indicated the presence of a ring around Haumea. This represents the first ring system discovered for a TNO.Surprise! Dwarf Planet Haumea Has a Ring, Sky and Telescope, October 13, 2017. The ring has a radius of about 2,287 km, a width of ~70 km and an opacity of 0.5.

Such behavior indicates that the ring is not optically thin. Indeed, occultation observations conducted from the ground and the spacecraft showed that its normal optical depth varies between 0.5 and 2.5, being highest near the periapsis. The equivalent depth of the ε ring is around 47 km and is invariant around the orbit. A close-up view of the (from top to bottom) δ, γ, η, β and α rings of Uranus.

The occultation data is consistent with a pressure of at most 4 microbar for a global atmosphere of Vanth. Vanth does not resemble other known collisional satellites because its spectrum is very different from that of its primary. Vanth may thus be a captured Kuiper belt object. In that respect, it may be similar to the satellite of another possible dwarf planet, Gonggong, which also has a very different colour compared to its primary.

10199 Chariklo, a centaur, was the first minor planet discovered to have rings. It has two rings, perhaps due to a collision that caused a chain of debris to orbit it. The rings were discovered when astronomers observed Chariklo passing in front of the star UCAC4 248-108672 on June 3, 2013 from seven locations in South America. While watching, they saw two dips in the star's apparent brightness just before and after the occultation.

The ACE-FTS instrument is the main payload of the SCISAT-1 spacecraft. The primary scientific goal of the Atmospheric Chemistry Experiment (ACE) is to measure and understand the chemical and dynamical processes that control the distribution of ozone in the upper troposphere and stratosphere. The principle of ACE measurement is the solar occultation technique. A high inclination (74 degrees), low Earth orbit will provide ACE coverage of tropical, mid-latitudes and polar regions.

The current Picosat 9 is a British-built (US DOD-funded) microsatellite (67 kg) to test electronic components/systems in space conditions. Oboard this model carries four test payloads: Polymer Battery Experiment (PBEX), Ionospheric Occultation Experiment (IOX), Coherent Electromagnetic Radio Tomography (CERTO) and On Orbit Mission Control (OOMC) an ultra-quiet platform (OPPEX). PICOSat flies in an 800 km circular orbit with a 67 degree inclination. PICOSat uses a gravity gradient boom for stabilization.

The smallest KBO yet detected was discovered in 2009 by poring over data from the Hubble Space Telescope's fine guidance sensors. Astronomers detected a transit of an object against a distant star, which, based on the duration and amount of dimming, was calculated to be a KBO about in diameter. It has been suggested that the Kepler observatory may be able to detect objects in the Oort cloud by their occultation of background stars.

A magnetometer and data logger are installed at The Cottage to collect data for Dr. Yuki Obana of the Osaka Electro-Communication University. The data is used for solar wind research. Society members are very active in occultation observation using the C14 telescope housed in the Beverly-Begg Observatory with a Watec astronomical video camera and IOTA-VTI video timing system. A SBIG ST8300M camera is used for Astrometry and Photometry in several observation programs.

The reappearance of Hujjat-Allah al-Mahdi is a belief in Twelver Shia eschatology that the twelfth Imam, Hujjat-Allah al-Mahdi, will return at an unspecified time and establish an Islamic state of peace and justice. This will be the end of the Major Occultation, the period since he became "hidden" in 941 CE. This reappearance will be foreshadowed by a number of signs, such as the sun rising from the West.

Born in Samarrah in 868 CE, the twelfth Imam was the son of Hasan al-Askari. Until his father was killed, al-Mahdi lived under the protection of his father and companions was hidden from mankind by God. Only appointed deputies were allowed to meet him during the Minor Occultation, the period of his life from age 5 to 73. Al- Mahdi communicated with Shia Muslims via the Four Deputies during this period.

The planets (as well as the Moon) have > the nature of water and reflect light. The light pouring forth from the Sun > does not always reach the moon owing to the obstruction of the earth > itself—this is called 'an-xu', a lunar eclipse. When (a similar effect) > happens with a planet (we call it) an occultation; when the Moon passes > across (the Sun's path) then there is a solar eclipse.Needham (1986), Volume > 3, 414.

60 Cancri is a star in the zodiac constellation Cancer, located about 850 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of +5.44. 60 Cancri is situated near the ecliptic, so it is subject to the occasional occultation by the Moon. It is moving away from the Earth with a heliocentric radial velocity of +25 km/s.

Mars 6 lander transmitted data during descent, but failed upon impact. Mars 4 flew by the planet at a range of 2200 km returning one swath of pictures and radio occultation data, which constituted the first detection of the nightside ionosphere on Mars. Mars 7 probe separated prematurely from the carrying vehicle due to a problem in the operation of one of the onboard systems (attitude control or retro-rockets) and missed the planet by .

'Ali ibn al-Hasan al-Ta'i al-Tatari (a companion of Musa al- Kadhim) named Musa al-Kadhim as the hidden Imam. In defense of his view he wrote Kitab al-Ghayba, which became the framework for the works of later Waqifite authors on the issue of al-Ghayba (the occultation). One such author was Al-Hasan ibn Muhammad ibn Suma`a (d. 263 A.H. / 877 C.E.), the Waqifite student of al-Ta'i al-Tatari.

Muhammad al-Mahdi, otherwise known as the Twelfth Imam, went into hiding in 873 at the age of four. His father was al-`Askari, who had been murdered; and so he was hidden from the authorities of the Abbasid Caliphate. He maintained contact with his followers until 940, when he entered the Occultation. Twelverism believes that al-Mahdi is the current Imam, and will emerge at the end of the current age.

847 Agnia is a minor planet orbiting the Sun. It is approximately 28 kilometers in diameter.IOTA/IOTA-ES occultation update for (847) Agnia The spectrum of this object indicates that it is an S-type asteroid with both low and high calcium forms of pyroxene on the surface, along with less than 20% olivine. The high-calcium form of pyroxene forms 40% or more of the total pyroxene present, indicating a history of igneous rock deposits.

However, when Shia states arose in later centuries, since the hidden Imam was alive and was the leader of Muslims, the role of the Shia states among Shia communities was in question. This problem has caused continuing tension between government and religion throughout Shia history. The occultation has resulted in many people claiming to be the returned Mahdi. According to seminary expert, Mehdi Ghafari, more than 3,000 fake Mahdis were in prison in Iran in 2012.

Two stellar occultations by Lucina have been observed so far, in 1982 and 1989. During the first event, a possible small satellite with an estimated 5.7 km diameter was detected at a distance of 1,600 km from 146 Lucina. A 1992 search using a CCD failed to discover a satellite larger than 0.6 km, although it may have been obscured by occultation mask. Further evidence for a satellite emerged in 2003, this time based on astrometric measurements.

Two Planet-hunters Snapped at La Silla Observatory. To find extra solar planets, CoRoT uses the method of transits detection. The primary transit is the occultation of a fraction of the light from a star when a celestial object, such as a planet, passes between the star and the observer. Its detection is made possible by the sensitivity of CCD to very small changes in light flux. Corot is capable of detecting changes in brightness of about 1/10,000.

This was the closest flyby up to this date, and provided the opportunity to obtain more detailed data on the constituents in the upper atmosphere of Titan. A first analysis of that data showed a large range of complex carbon molecules. On 25 April a mass plot was published that demonstrates the existence of these molecules. 3 May 2005 – Cassini begins Radio occultation experiments on Saturn's Rings, to determine ring particle size distribution, on the scale of centimetres.

Before the shift of Dawat in India Dai's representative were known as Wali-ul-Hind. Syedi Hasan Feer was one of the prominent Ismaili wali of 14th century. The line of Tayyib Dais that began in 1132 is still continuing under the main sect known as Dawoodi Bohra (see list of Dai of Dawoodi Bohra). The Mustaali split several times over disputes regarding who was the rightful Dāʿī al-Muṭlaq, the leader of the community within The Occultation.

Four close associates of his father, known as The Four Deputies, became mediators between the Imam and his followers known as Sufara until the year 941. This period is considered by Twelvers to be the first, or minor occultation. When believers faced difficulty, they would write their concerns and send them to his deputy. The deputy would receive the decision of the Imam, endorse it with his seal and signature, and return it to the concerned parties.

During the observations in June 2013, Warner also noted that Carlwirtz is likely a synchronous binary asteroid with a minor-planet moon in its orbit. While the satellite dimension could not be determined, it has an orbital period of 16.11 hours with an estimated semi-major axis of 6.1 kilometers. However, neither in 2013 nor in the 2018-observations any eclipsing/occultation events could be detected. Instead the asteroid has a classically shaped bimodal lightcurve instead.

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Eurymedon measures 36.96 kilometers in diameter and its surface has an albedo of 0.082, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 44.22 kilometers based on an absolute magnitude of 10.5. In December 2011, an observed asteroid occultation event gave a cross section of (no fit).

Weywot is estimated to be around in diameter, based on a stellar occultation by Weywot in 2019. Weywot was estimated to be in diameter, based on observations with the Herschel Space Observatory in 2013. Prior to the Herschel Space Observatory measurements, Weywot was measured be about 74 km ( of Quaoar) according to its apparent magnitude, under the assumption that Weywot has an equal albedo and density to Quaoar. Weywot is estimated to only have the mass of Quaoar.

Yinghuo-1's primary scientific objectives were: # To conduct detailed investigation of the plasma environment and magnetic field around Mars. # To study Martian ion escape processes and their possible mechanisms # To conduct ionosphere occultation measurements between Yinghuo-1 and Fobos-Grunt, focusing on the sub-solar and midnight regions. # To observe sandstorms on the Martian surface. The probe's science payload consisted of four instrument: # A plasma package, consisting of an electron analyzer, ion analyzer and mass spectrometer.

1437 Diomedes is a large Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 3 August 1937, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The dark D/P-type asteroid belongs to the largest Jupiter trojans and has a notably elongated shape and a longer than average rotation period of 24.49 hours. Diomedes was the first Jupiter trojan successfully observed during an occultation event of star.

TAOS is a joint effort of the Academia Sinica Institute of Astronomy and Astrophysics, Harvard-Smithsonian Center for Astrophysics, Lawrence Livermore National Laboratory, The Institute of Geophysics and Planetary Physics, National Central University, Institute of Astronomy and Yonsei University, South Korea. Currently, an expansion to the TAOS project is being planned called TAOS II, with a new meaning to the acronym, the Transneptunian Automated Occultation Survey. The data volume is expected to be over 300 terabytes per year.

Infrared spectroscopy, including measurements with Spitzer Space Telescope (SST), and UV occultation observations, found trace amounts of complex hydrocarbons in the stratosphere of Uranus, which are thought to be produced from methane by photolysis induced by solar UV radiation. They include ethane , acetylene , methylacetylene , diacetylene . Infrared spectroscopy also uncovered traces of water vapour, carbon monoxide and carbon dioxide in the stratosphere, which are likely to originate from an external source such as infalling dust and comets.

From the perspective of Usuli jurisprudence, during the occultation of the Mahdi, Shia hawzah clerics are his representatives, with responsibility for understanding and explaining Islamic religious jurisprudence. Shiite authorities in the history of Shi'ism have an important role in the religious, political and social thought of their communities. One example is the fatwa of Mirza Mohammed Hassan Husseini Shirazi imposing sanctions on the use of tobacco during Qajar rule, which led to the abolition of the tobacco concession.

9, THE CULT OF ALID SAINTS IN THE FATIMID MONUMENTS OF CAIRO, PART II: THE MAUSOLEA , By :CAROLINE WILLIAMS, page 47 According to Ṭayyibī Musta'lid tradition, before Ṭayyib went into the Occultation, his father Al-Amir had instructed Queen al-Hurrah Arwa bint Ahmad in Yemen to anoint a vicegerent after the seclusion, the Da'i al-Mutlaq, who as the Imam's vicegerent has full authority to govern the community in all matters both spiritual and temporal.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Varsavia measures between 34.15 and 51.44 kilometers in diameter, and its surface has an albedo between 0.042 and 0.10. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0874 and adopts a diameter of 41 kilometers, obtained from modeled data and a directly observed minor planet occultation of a star.

It has an average distance of 39 AU from the Sun, hence in-depth data from Pluto is sparse and difficult to gather. Temperature is inferred indirectly for Pluto; when it passes in front of a star, observers note how fast the light drops off. From this, they deduce the density of the atmosphere, and that is used as an indicator of temperature. Pluto's atmosphere backlit by the Sun One such occultation event happened in 1988.

10199 Chariklo is the largest confirmed centaur (small body of the outer Solar System). It orbits the Sun between Saturn and Uranus, grazing the orbit of Uranus. On 26 March 2014, astronomers announced the discovery of two rings (nicknamed as the rivers Oiapoque and Chuí) around Chariklo by observing a stellar occultation, making it the first minor planet known to have rings. Chariklo was discovered by James V. Scotti of the Spacewatch program on February 15, 1997.

Occultation phenomena permitted a determination of the scattering properties of the lunar limb. The dielectric constant of the lunar subsurface in the scattering region below a depth of about 25 cm was then determined from a profile of reflectivity values vs the angle of incidence on the Moon. The mean lunar slope over each area from which signals were reflected has also been inferred. The observations were located within about 10 degrees of the lunar equator.

In 2004, it was announced that Tama has a minor-planet moon, provisionally designated . The satellite was identified based on lightcurve observations with mutual occultation and eclipsing events from 24 December 2003 to 5 January 2004 by Raoul Behrend, René Roy, Claudine Rinner, Pierre Antonini, Petr Pravec, Alan Harris, Stefano Sposetti, Russell Durkee, and Alain Klotz. The moon measures approximately 9 kilometers in diameter. It may orbits 20 km away in a period of 16.4442 hours (synchronously).

The deeper of the two eclipses is called the primary regardless of which star is being occulted, and if a shallow second eclipse also occurs it is called the secondary eclipse. The size of the brightness drops depends on the relative brightness of the two stars, the proportion of the occulted star that is hidden, and the surface brightness (i.e. effective temperature) of the stars. Typically the occultation of the hotter star causes the primary eclipse.

The orbits of the moon and stars are sufficiently inclined that the inhabitants of the planet have seldom seen an eclipse or occultation. McLaughlin pays homage to Asimov by naming the protagonist "Isak" and naming a historical figure Duke "Lagash", the name of the planet in "Nightfall". While Asimov simply used the Greek letters Alpha, Beta, Gamma, etc. to name the stars in his story, McLaughlin named his stars Alpher, Bethe, Gamow, Dalton, Ephron, and Zwicky.

In Ancient Greece, the planet was known as . In the fourth century BCE, Aristotle noted that Mars disappeared behind the Moon during an occultation, indicating that the planet was farther away. Ptolemy, a Greek living in Alexandria, attempted to address the problem of the orbital motion of Mars. Ptolemy's model and his collective work on astronomy was presented in the multi-volume collection Almagest, which became the authoritative treatise on Western astronomy for the next fourteen centuries.

Through the mid-20th century, additional mass estimates using this technique would be performed by Marie-Charles Damoiseau, John Couch Adams, Ralph Allen Sampson, and Willem de Sitter, all of which were less than the modern value with the closest being Sampson's 1921 estimate of 4.5 of the mass of Jupiter, which was 4% less than the currently accepted mass. Io's diameter was estimated using micrometer measurements and occultations of background stars by Io. Edward E. Barnard used a micrometer at the Lick Observatory in 1897 to estimate a diameter of , 8.5% larger than the accepted modern value, while Albert A. Michelson, also using the Lick telescope, came up with a better estimate of . The best pre- spacecraft estimate of Io's diameter and shape came from the observations of an occultation of the star Beta Scorpii C on May 14, 1971, where a diameter of was found, slightly less the accepted modern value. These measurements allowed astronomers to estimate Io's density, given as 2.88 g/cm3 following the Beta Scorpii occultation.

Chariklo is the largest confirmed member of a class of small bodies known as centaurs, which orbit the Sun between Saturn and Uranus in the outer Solar System. Forecasts had shown that, as seen from South America, it would pass in front of the 12.4-magnitude star UCAC4 248-108672, located in the constellation Scorpius, on 3 June 2013. Video showing the occultation of the star UCAC4 248-108672 by Chariklo and the corresponding lightcurve With the aid of thirteen telescopes located in Argentina, Brazil, Chile, and Uruguay, a team of astronomers led by Felipe Braga Ribas (), a post-doctoral astronomer of the National Observatory (ON), in Rio de Janeiro, and 65 other researchers from 34 institutions in 12 countries, was able to observe this occultation event, a phenomenon during which a star disappears behind its occulting body. The 1.54-metre Danish National Telescope at La Silla Observatory, due to the much faster data acquisition rate of its 'Lucky Imager' camera (10 Hz), was the only telescope able to resolve the individual rings.

It is named for Beatrice Portinari, beloved of Dante Alighieri and immortalized by him in La Vita Nuova and The Divine Comedy. On February 16, 2001, an occultation of a magnitude +9.09 star by this asteroid was observed from three locations. The resulting chords matched an elliptical profile with a mean radius of 35.9 km. The observers noted some dimming and flickering at the beginning of the event, which may indicate the star was binary or the asteroid has an irregular shape.

Both represent stages in the evolution of a star after it has exhausted the hydrogen at its core. This energy is being radiated from the star's outer envelope at an effective temperature of 14,990 K, which produces the blue-white hue typical of B-type stars. In the past, this star catalogued as a spectroscopic binary and a companion was apparently detected through lunar occultation. However, it is most likely a solitary star and any nearby stars are merely optical companions.

Edward Fomalont (born May 14, 1940) is an American scientist working at the National Radio Astronomy Observatory. He specializes in radio galaxies, X-ray binary systems, astrometry, and general relativity. He has published more than 330 papers in peer-reviewed journals and proceedings of scientific conferences. In 1975, Fomalont and Richard Sramek made a first radio- interferometric occultation experiment to test the theory of general relativity by measuring the bending of microwave radiation in the gravitational field of the Sun.

On 7 November 2006, the first stellar occultation by the satellite of an asteroid (Linus) was successfully observed by a group of Japanese observers according to a prediction that was made just one day before by Berthier et al. based on more than 5 years of regular observations of Kalliope binary system using adaptive optics systems on ground-based telescopes. The observed chords of Linus give a unique opportunity to estimate the size of the moonlet which was estimated to 20–28 km.

This event was observed from 13 sites in the continental United States, allowing a cross-sectional profile to be determined. Based upon this study, the asteroid has a diameter of 136.4 ± 1.2 km. The geometric albedo calculated at the time of the occultation was 0.071 ± 0.002. 2012 photometric observations of this asteroid at the Organ Mesa Observatory in Las Cruces, New Mexico gave a light curve with a period of 13.175 ± 0.002 hours and a brightness variation of 0.09 ± 0.01 in magnitude.

But once he learned that the parliament that came out of it was to enact laws rather than apply the existing laws of Sharia, he turned against it. He argued that during the Occultation of the Muslim Messiah, Mahdi, an absolutist government which enforces Islamic law was the best government, considering it the lesser of the two evils in comparison to a secular parliamentarian government. His vigorous opposition to the movement led to his arrest by the Constitutionalist forces and his execution.

Adria (minor planet designation: 143 Adria) is a fairly large main-belt asteroid that was discovered by Austrian astronomer Johann Palisa on 23 February 1875, at the Austrian Naval Observatory, and named after the Adriatic Sea, on the coast of which the discovery was made. This dark-coloured asteroid has probably a primitive carbonaceous chondritic composition. One occultation by Adria has been reported so far, from Japan on August 21, 2000. A somewhat spherical shape measuring 98 × 86 km was observed.

He is also one of the co-discoverers of Pluto's moons, Nix and Hydra. occultation campaign to observe 486958 Arrokoth before the New Horizons fly-by of the Kuiper belt object in January 2019. He has been working with the Deep Ecliptic Survey team who have been responsible for the discovery of over 1,000 Kuiper belt objects (KBOs). Beyond the work of just locating these objects, he additionally seeks to develop a better picture of the structure and nature of them.

The orbits of the moons are confirmed to be circular and coplanar, with inclinations differing less than 0.4° and eccentricities less than 0.005. The discovery of Nix and Hydra suggested that Pluto could have a ring system. Small-body impacts can create debris that can form into a ring system. However, data from a deep-optical survey by the Advanced Camera for Surveys on the Hubble Space Telescope, by occultation studies, and later by New Horizons, suggest that no ring system is present.

This minor planet was named in honor of its discoverer, the American astronomer Edward L. G. Bowell (born 1943), based on a proposal by MPC's longtime director Brian G. Marsden. Astronomer at the Lowell Observatory and a prolific discoverer of minor planets himself, Bowell has made significant contributions on the observatory's UBV photometry and astrometry programs for minor planets, including the prediction of occultation events. The official naming citation was published by the Minor Planet Center on 1 January 1981 ().

During the photometric observations in 2007, it was also revealed that Duponta is a synchronous binary asteroid with a minor-planet moon orbiting it every 17.57(8) hours. Based on mutual eclipse and occultation events with a magnitude between 0.06 and 0.12, the binary system has a mean-diameter ratio of , which translates into a diameter of 1.77 kilometers for the satellite. The minor planet moon has received the provisional designation . It has an estimated semi-major axis of 14 kilometers.

This minor planet was named in honor of American astronomer Alan Hale (born 1958), co-discoverer of comet Hale–Bopp. His precise visual observations include more than 130 comets, several at more than one apparition, and both, magnitude estimates and confirmations of discoveries. He has also skillfully estimated the magnitudes of the near-Earth objects, 4179 Toutatis and , and has performed asteroid occultation. Hale has promoted the study of small Solar System bodies in articles and in his astronomy lectures.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Centenaria measures between 50 and 71 kilometers in diameter and its surface has an albedo between 0.046 and 0.072. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0469 and a diameter of 58.61 kilometers based on an absolute magnitude of 10.1. An asteroid occultation from July 2007 measured as cross-section of .

Epsilon Piscium (Epsilon Psc, ε Piscium, ε Psc) is the Bayer designation for a star approximately away from the Earth, in the constellation Pisces. It is a yellow-orange star of the G9 III or K0 III spectral type, meaning it has a surface temperature around 5,000 kelvins. This is a normal giant star, slightly cooler in surface temperature, yet brighter and larger than the Sun. It is a suspected occultation double, with both stars having the same magnitude, separated by 0.25 arcsecond.

The first of these planetary rings was detected in 1968 by a team led by Edward Guinan. In the early 1980s, analysis of this data along with newer observations led to the hypothesis that this ring might be incomplete. Evidence that the rings might have gaps first arose during a stellar occultation in 1984 when the rings obscured a star on immersion but not on emersion. Images from Voyager 2 in 1989 settled the issue by showing several faint rings.

The presence of a relatively large satellite, Vanth, may change them considerably. The absolute magnitude of Vanth is estimated at 4.88, which means that it is about 11 times fainter than Orcus itself. The ALMA submillimeter measurements taken in 2016 showed that Vanth has a relatively large size of with albedo of about 8 percent while Orcus's has a slightly smaller size of . Using a stellar occultation by Vanth in 2017, Vanth's diameter has been determined to be , with an uncertainty of .

The haze is the most probable reason for a kink in the curve of light intensity vs. time obtained by New Horizons during the flight through Pluto's shadow (see image on right) – below altitude the atmosphere attenuates light much stronger than above. A similar kink was observed during stellar occultation in 1988. Firstly it was also interpreted as weakening of light by haze, but now it is thought to be mainly a result of strong inverse temperature gradient in lower atmosphere.

Curves of pressure vs. distance from the center, obtained from occultations in 1988 and 2002, in combination with the now known radius of Pluto () give values of about for 1988 and for 2002. Spectral data provided values in 2008 and in 2012 for the distance from the center (1±4 km from the surface). An occultation on 4 May 2013 gave data almost precisely for the surface level (1190 km from the center, or 3±4 km from the surface): .

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Teucer measures between 89.43 and 113.99 kilometers in diameter and its surface has an albedo between 0.059 and 0.073. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0435 and a diameter of 110.72 kilometers based on an absolute magnitude of 8.8. In June 2014, an observed asteroid occultation gave a cross-section of (poor fit).

After the discovery of Astraea, thousands of other asteroids would follow. Indeed, the discovery of Astraea proved to be the starting point for the eventual demotion of the four original asteroids (which were regarded as planets at the time) to their current status, as it became apparent that these four were only the largest of a whole new type of celestial body. An occultation on 6 June 2008 produced an effective diameter (silhouette) of . Astraea has been studied by radar.

Once the lightcurve has been recorded the chord across the occulting object can be determined via calculation. By using the start and end times of the occultation event the position in space of both the observer and the occulting object can be worked out (a process complicated by the fact that both the object and the observer are moving). Knowing these two locations, combined with the direction to the background object, the two endpoints of the chord can be determined using simple geometry.

In 2010, the thermal radiation of Dziewanna was observed by the Herschel Space Telescope, which allowed astronomers to estimate its diameter at about . A stellar occultation by Dziewanna was observed on 17 May 2019, yielding a single-chord diameter of . Published in May 2013, a rotational lightcurve for this minor planet was obtained from photometric observations at the discovering observatory with the 2.5-meter Irénée du Pont Telescope. It gave a rotation period of hours with a brightness variation of 0.12 magnitude ().

The photometric observations obtained by Brian Warner and collaborators during 2–12 November 2005, revealed that Holmes is a synchronous binary asteroid with a minor- planet moon orbiting it every 24.4 hours at an estimated average distance of . The discovery was announced immediately on 15 November 2005. The mutual occultation events indicated the presence of a satellite 37% the size of its primary, which translates into an estimated diameter of kilometers depending on the underlying size estimate of the primary.

The obtained lightcurves from the combined photometric observations gave a well-defined rotation period of 4.5609 hours, a brightness variation of 0.18 magnitude (), and orbital period of 24.22 hours for the asteroid's moon. However, as no mutual occultation/eclipsing events were observed, the binary nature of Sharp remains unconfirmed. The "Johnstonsarchive" estimates that the moon has a semi-major axis of 4.5 kilometers. No diameter estimate for the moon was published, as a secondary- to-primary mean-diameter ratio could not be derived.

During the photometric observation by Warner and Coley in January 2013 (see above), mutual occultation and eclipsing events revealed that Shumarinaiko is a synchronous binary asteroid with an elongated minor-planet moon in orbit. The satellite, provisionally designated , seems to be tidally locked to its orbital period of 14.409 hours. It measures least 16% of its primary (Ds/Dp of <), which translates into a diameter of approximately 830 meters. There are more than 100 binary asteroids known to exist in the asteroid belt.

After being already recognized as an asteroid pair, American astronomer Brian Warner observed faint mutual eclipsing and occultation events in April 2013. After repeated lightcurve subtraction, he was able to show that Wasserburg is likely a binary system with a minor-planet moon orbiting it every 15.97 hours. Assuming a depth of 0.03 magnitude, he estimated a secondary-to-primary mean-diameter ratio of . The Johnston's archive derives a diameter of meters for the satellite, based on the primary diameter given by WISE.

Of the asteroids with a diameter greater than 75 km, only 4 Vesta has a higher known albedo. Dembowska and 16 Psyche have orbits that repeat themselves almost exactly every five years in respect to their position to the Sun and Earth. In 1988 a search for satellites or dust orbiting this asteroid was performed using the UH88 telescope at the Mauna Kea Observatories, but the effort came up empty. There was one occultation on October 31, 2006, and on December 5, 2007.

A ring around Haumea, a dwarf planet and resonant Kuiper belt member, was revealed by a stellar occultation observed on 21 January 2017. This makes it the first trans-Neptunian object found to have a ring system. The ring has a radius of about 2,287 km, a width of ≈70 km and an opacity of 0.5. The ring plane coincides with Haumea's equator and the orbit of its larger, outer moon Hi’iaka (which has a semimajor axis of ≈25,657 km).

Stellar occultation events indicate that Gǃkúnǁʼhòmdímà has an effective (equivalent-sphere) diameter of 600–670 km, but is not spherical. Due to complications from its non-spherical shape, the rotational period cannot be definitely determined from current light-curve data, which has an amplitude of Δm = 0.03 ± 0.01 mag, but the simplest solution is 11.05 hours. It is almost certainly between that and 41 hours. The system mass is , about 2% that of Earth's moon and a bit more than Saturn's moon Enceladus.

Nereid was discovered on 1 May 1949 by Gerard P. Kuiper on photographic plates taken with the 82-inch telescope at the McDonald Observatory. He proposed the name in the report of his discovery. It is named after the Nereids, sea-nymphs of Greek mythology and attendants of the god Neptune. It was the second and last moon of Neptune to be discovered before the arrival of Voyager 2 (not counting a single observation of an occultation by Larissa in 1981).

The 11th Imam, Abdullah al-Mahdi Billah, founded the Fatimid Caliphate in 909 CE in Ifriqiya (which includes present Tunisia in North Africa), ending the first occultation. In Ismāʿīlī eyes this act again united the Imamate and the Caliphate in one person. The Fatimids then extended up to the central Maghreb (now including Morocco, Algeria and Libya). They entered and conquered Egypt in 969 CE during the reign of the fourteenth Imam, al-Mu'izz li-Din Allah, and made Cairo their capital.

In contrast, the daily practices of humiliation and abuse in some prison settings in the USA get almost no public attention. In various circumstances, certain social sub-groups and situations may have attention deflected away; this deflection may be institutionalized in media bias. As a dynamic of political or social intolerance, when segregation is not possible or desirable, social occultation may be found in individual behaviors and in organizational policies. Outgroups have frequently sought visibility as a vehicle to address issues of concern.

Communication with the spacecraft then ceased as it passed behind the planet. The radio occultation data allowed the temperature structure of the outer atmosphere to be measured, showing a temperature inversion between the altitudes with 10 and 100 mbar pressures. Temperatures at the 10 mbar level ranged from , while temperatures at the 100 mbar level were . The spacecraft generated an infrared map of the planet, which confirmed the idea that the planet radiated more heat than it received from the Sun.

The CGRO was designed to image continuous radiation and to detect bursts. MSFC was responsible for the Burst and Transient Source Experiment, (BATSE). This triggered on sudden changes in gamma count-rates lasting 0.1 to 100 s; it was also capable of detecting less impulsive sources by measuring their modulation using the Earth occultation technique. In nine years of operation, BATSE triggered about 8000 events, of which some 2700 were strong bursts that were analyzed to have come from distant galaxies.

Two ultraviolet spectrometers were involved in this experiment, one to measure UV absorption, the other to sense UV emissions. The occultation spectrometer scanned Mercury's edge as it passed in front of the Sun, and detected whether solar ultraviolet radiation was absorbed in certain wavelengths, which would indicate the presence of gas particles, and therefore an atmosphere.Dunne and Burgess 1978, pp. 25-26 The airglow spectrometer detected extreme ultraviolet radiation emanating from atoms of gaseous hydrogen, helium, carbon, oxygen, neon, and argon.

Aegle (minor planet designation: 96 Aegle) is a carbonaceous asteroid and the namesake of the Aegle family located in the outer regions of the asteroid belt, approximately in diameter. It was discovered on 17 February 1868, by French astronomer Jérôme Coggia at the Marseille Observatory in southeastern France. The rare T-type asteroid has a rotation period of 13.8 hours and has been observed several times during occultation events. It was named after Aegle, one of the Hesperides (nymphs of the evening) from Greek mythology.

Objects which exhibit retrograde motion (such as planets) occasionally display an appulse event without an associated conjunction event. In these cases, the two objects appear to approach each other, but turn away before reaching a momentary coincidence of right ascension. When the celestial bodies appear so close together that one actually passes in front of the other, the event is classified as a transit, occultation, or eclipse, and not an appulse. Appulses are naked-eye events for general observers when involving bright planets and the Moon.

Radar image of near-Earth asteroid (53319) 1999 JM8 The following list of instrument-resolved minor planets consists of minor planets whose disks have been resolved, whether by telescope, a visit by an uncrewed spacecraft, or by observing the occultation of a background star from multiple sites. Disk resolution allows the density of an body to be computed, providing useful information about the internal composition. It can also be used to determine the shape of the object, to search for albedo features, and to look for companions.

The hidden saints live among the people and are aware of them, but the people do not know them. Sura Kahf 18:65–66 implies that even though people do not know the hidden saints, they benefit from them like the sun hidden behind the clouds. Shias generally believe that in every age, there is an Imam, either apparent or hidden. But in times that there are dangers threatening the life of the Imam, he is concealed by God's order, hence the Occultation of the twelfth Imam.

According to Jassim M. Hussain, the majority of the Imamites denied his birth or even his existence, and abandoned their belief in the hidden Imam except for a small minority belonging to the circles of narrators, like Ibn Qubba and al-Nu'mani who based their belief on the traditions of the Imams (i.e. Hadith about twelve Imams). Jassim Hussain indicates, several books were written before the minor Occultation predicting the event of the twelfth Imam being the Mahdi and his going to occultation.Hussain, Jassim M. (1986).

Sophrosyne (minor planet designation: 134 Sophrosyne) is a large main-belt asteroid that was discovered by German astronomer Robert Luther on 27 September 1873, and was named after the concept of sophrosyne, Plato's term for 'moderation'. Classified as a C-type asteroid, it has an exceedingly dark surface and most probably a primitive carbonaceous composition. An occultation of a star by 134 Sophrosyne was observed 24 November 1980, in the United States. Timing information from this event allowed a diameter estimate of 110 km to be derived.

In May 2005, Cassini began a series of radio occultation experiments, to measure the size-distribution of particles in Saturn's rings, and measure the atmosphere of Saturn itself. For over four months, the craft completed orbits designed for this purpose. During these experiments, it flew behind the ring plane of Saturn, as seen from Earth, and transmitted radio waves through the particles. The radio signals received on Earth were analyzed, for frequency, phase, and power shift of the signal to determine the structure of the rings.

The Minor Occultation (, ') refers to the period when the Twelver Shia believe the Imam still maintained contact with his followers via deputies (, '). During this period, lasting from 874 to 941, the deputies represented him and acted as agents between him and his followers. Shia believe that in 873, after the death of his father, the eleventh Imam, Hasan al-Askari, the 12th Imam was hidden from the authorities of the Abbasid Caliphate as a precaution. His whereabouts were disclosed only to a select few.

Some scholars, including Bernard Lewis, point out that the idea of an Imam in occultation was not new in 873 but that it was a recurring factor in Shia history. Examples of this include the cases of Muhammad ibn al- Hanafiyyah (according to the Kaysanites), Muhammad al-Nafs al-Zakiyya, Musa al-Kadhim (according to the Waqifite Shia), Muhammad ibn Qasim (al-Alawi), Yahya ibn Umar and Muhammad ibn Ali al-Hadi.The Assassins: A Radical Sect in Islam, Bernard Lewis, pp. 23, 35, 49.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Rhodesia measures between 46.43 and 52.276 kilometers in diameter and its surface has an albedo between 0.0548 and 0.0783. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0666 and a diameter of 47.40 kilometers based on an absolute magnitude of 10.18. In August 2015, an occultation by Rhodesia determined a cross-section of 48.0 × 48.0 kilometers (no fit).

The faint tertiary star, Eta Virginis B, orbits the inner group in a wider orbit over a period of 13.1 years. Eta Virginis is 1.97 degrees north of the ecliptic, so it can be occulted by the Moon and (rarely) by planets. On October 12, 272 BC the ancient Greek astronomer Timocharis observed a conjunction of the star with Venus. The last occultation by a planet took place on September 27, 1843, also by Venus, which will occult it again on November 19, 2445.

A spatially resolved submillimeter imaging of Orcus–Vanth system in 2016 showed that Vanth has a relatively large size of , with an uncertainty of . That estimate for Vanth is in good agreement with the size of about derived from a stellar occultation in 2017. Like Charon compared to Pluto, Vanth is quite large compared to Orcus, and is one reason for characterizing Orcus as the 'anti-Pluto'. If Orcus is a dwarf planet, Vanth would be the third-largest known dwarf-planet moon, after Charon and Dysnomia.

This is mainly due to atmospheric refraction (not absorption or scattering). The first such observations were made on 19 August 1985 by Noah Brosch and Haim Mendelson of the Wise Observatory in Israel. But quality of the data was rather low due to unfavorable observational conditions (in addition, the detailed description was published only 10 years later). On 9 June 1988 the existence of the atmosphere was convincingly proven by occultation observations from eight sites (the best data were obtained by the Kuiper Airborne Observatory).

LORRI and MVIC attempted to overlap their respective coverage areas to form stereo pairs. LEISA obtained hyperspectral near-infrared maps at globally and for selected areas. Patterns of blue-gray ridges and reddish material observed in the Tartarus Dorsa region on July 14, 2015 Meanwhile, Alice characterized the atmosphere, both by emissions of atmospheric molecules (airglow), and by dimming of background stars as they pass behind Pluto (occultation). During and after closest approach, SWAP and PEPSSI sampled the high atmosphere and its effects on the solar wind.

The optical depth of the λ ring shows strong wavelength dependence, which is atypical for the Uranian ring system. The equivalent depth is as high as 0.36 km in the ultraviolet part of the spectrum, which explains why λ ring was initially detected only in UV stellar occultations by Voyager 2. The detection during a stellar occultation at the wavelength 2.2 μm was only announced in 1996. The appearance of the λ ring changed dramatically when it was observed in forward-scattered light in 1986.

The star is positioned near the ecliptic and thus is subject to occultation by the Moon. This is an aging K-type giant star with a stellar classification of , which means it has exhausted the hydrogen at its core and evolved away from the main sequence. The suffix notation indicates a mild underabundance of iron in the atmosphere. It has expanded to 37 times the Sun's radius and is radiating over a thousand times the Sun's luminosity from its photosphere at an effective temperature of 4,001 K.

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Ursula measures between 189.45 and 215.67 kilometers in diameter and its surface has an albedo between 0.04 and 0.049. Observations of an occultation on 15 November 1984, produced six chords indicating an estimated diameter of 216±10 km. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0494 and adopts a diameter of 216.1 kilometers based on an absolute magnitude of 7.21.

MORIS (MIT Optical Rapid Imaging System) s a high-speed, visible-wavelength camera for use on IRTF using an electron multiplying CCD. MORIS is mounted on the side window of SpeX, and is fed by the internal cold dichroic in SpeX. The design is based on POETS (Portable Occultation, Eclipse, and Transit Systems), which were developed by a collaboration between MIT and Williams College. MORIS is available for open use on IRTF and its user interface has been converted to the IRTF standard interface.

Iduna (minor planet designation: 176 Iduna) is a large main-belt asteroid that was discovered by German-American astronomer Christian Heinrich Friedrich Peters on October 14, 1877, in Clinton, New York. It is named after Sällskapet Idun, a club in Stockholm that hosted an astronomical conference; Idun is also a Norse goddess. A G-type asteroid, it has a composition similar to that of the largest main-belt asteroid, 1 Ceres. An occultation of a star by Iduna was observed from Mexico on January 17, 1998.

Initial orbital parameters were 140 x 140 kilometers at 40.58° inclination. Soon afterward, the spacecraft began its main imaging mission — providing panoramic images of the mountainous region of the Moon between 30° and 60° south latitude and between 20° and 80° east longitude. Other scientific experiments included extensive studies on the shape and strength of the lunar gravitational field and the locations of the mascons. Occultation experiments in May and June 1972 allowed scientists to determine the concentration of charged particles at an altitude of 10 kilometers.

The double refracting telescope at Le Houga was used extensively for studies of the planets and the teaching of young astronomers. In 1959 his observatory was part of an observational campaign regarding an occultation of Regulus by Venus. The team of Harvard observers at Le Houga was led by Gérard de Vaucouleurs, who had previously collaborated with Mr. Péridier on studies at the observatory. The success of the 1959 work started a five-year collaboration with NASA on photometry of the Moon and planets using a reflector.

Gǃkúnǁʼhòmdímà orbits the Sun at a distance of 37.5–107.9 AU once every 620 years and 2 months (226,517 days; semi-major axis of 72.72 AU). Its orbit has an eccentricity of 0.48 and an inclination of 23° with respect to the ecliptic. An eccentricity of 0.48 suggests that it was gravitationally scattered into its current eccentric orbit. It will come to perihelion in July 2046, and mutual occultation events with its satellite will begin in late 2050 and last most of that decade.

The Wellington City Council purchased the telescope for £2000 in 1923, and the telescope was shipped from Napier to Wellington. It was later transferred to the care of the Carter Observatory under the Carter Observatory Act (1938). At the Carter Observatory site, the Cooke telescope was used for solar astronomy research as well as flare star and double star monitoring programs over the following decades. In April 1968, Carter Observatory was one of the observatories involved in recording an occultation of Neptune by the Moon.

A stellar occultation in 2010 measured a single chord of . But this is only a lower limit for the diameter of because the chord may not have passed through the center of the body. In 2017, stellar occultations and data from its rotational lightcurve suggested that had an elongated shape, presumably due to its rapid rotation rate of 6.71 hours, similar to Haumea and Varuna. That would give approximate dimensions of 940 × 766 × 490 km, with its longest axis nearly twice as long as its polar axis.

In order to warn ships at sea of land, a system of hoisting a lantern with an oil wick lamp was introduced in 1843 by the British. A masonry pedestal was constructed in 1903 on the rampart of the fort and a double wick oil lamp inside the 4th order dioptric lens and lantern with arrangement for occultation was placed on this pedestal. The light was made available during fair seasons only, from September to May every year. In 1924, some enhancements were made.

Thomas Clausen Thomas Clausen (January 16, 1801, Snogbæk, Sottrup Municipality, Duchy of Schleswig (now Denmark) - May 23, 1885, Dorpat, Imperial Russia (now Estonia)) was a Danish mathematician and astronomer. Clausen learned mathematics at home. In 1820, he became a trainee at the Munich Optical Institute and in 1824, at the Altona Observatory after he showed Heinrich Christian Schumacher his paper on calculating longitude by the occultation of stars by the moon. He eventually returned to Munich, where he conceived and published his best known works on mathematics.

The Ionospheric Occultation Experiment (IOX) was a remote sensing satellite package that used a dual frequency Global Positioning System (GPS) receiver to measure properties of the ionosphere.Harvard University: Ionosphere Remote Sensing IOX demonstrated remote sensing techniques for future United States Department of Defense space systems and helped to improve operational models for ionospheric and thermospheric forecasts. IOX was developed by the United States Air Force Space and Missile Systems Center and was one of four experiment packages on PicoSAT, which was launched in September 2001.

For very large objects, with very well known orbital elements (like Pluto), diameters can be precisely measured by occultation of stars. For other large TNOs, diameters can be estimated by thermal measurements. The intensity of light illuminating the object is known (from its distance to the Sun), and one assumes that most of its surface is in thermal equilibrium (usually not a bad assumption for an airless body). For a known albedo, it is possible to estimate the surface temperature, and correspondingly the intensity of heat radiation.

In early 2017, its observations of 1 Ceres in the mid-infrared helped determine the large asteroid/dwarf planet was coated with a layer of asteroid dust from other bodies. In July 2017, SOFIA observed a star occultation of the distant Kuiper belt object 486958 Arrokoth while ground based observatories failed this observation, preparing the probe New Horizons visiting this asteroid. Sofia has been used also for Astrobiology missions, focusing amongst other goals on the observation of new planetary systems and the detection of complex molecules.

An artist's impression of a ring system around Chariklo The equivalent depth (a parameter related to the total amount of material contained in the ring based on the viewing geometry) of C1R was observed to vary by 21% over the course of the observation. Similar asymmetries have been observed during occultation observations of Uranus's narrow rings, and may be due to resonant oscillations responsible for modulating the width and optical depth of the rings. The column density of C1R is estimated to be 30–100 g/cm2.

This idea became influential afterwards, particularly in Shi'a Islam, where it became one of its central tenets. He was the first person to introduce the concept of Bada' (change in the divine will), when after defeat at the battle of Madhar, for which he had claimed he was promised victory, he said that God had changed his plan. His followers later developed into a distinct Shi'a sect known as the Kaysanites. They introduced the doctrines of Occultation (Ghayba) and Return (Raj'a) of the Mahdi.

There are also contributions from Gordon Jackson (acoustic guitar), Finley Barker and Tony Kelsey (guitars), Steve Winwood (organ, mandolin and bass), Bill Hunt, Levi French and Tony Ariss (pianos), Rob Harrison (bass) Steve Gibbons (backing vocals) and Greg Platt Lake (guitar and vocals). Kellie was prominent among the musicians featured on the six-CD Jess Roden Anthology, presented by Hidden Masters. He contributed to the 2011 sessions for the Distractions re-union album, The End of the Pier, which was released on Occultation Records in 2012.

Beta Virginis (β Virginis, abbreviated Beta Vir, β Vir), formally named Zavijava , is (despite its designation 'beta') the fifth-brightest star in the constellation of Virgo. Larger and more massive than the Sun, it is comparatively metal-rich (that is, it has a higher preponderance of elements heavier than helium). It is 0.69 degrees north of the ecliptic, so it can be occulted by the Moon and (rarely) by planets. The next planetary occultation of Zavijava will take place on 11 August 2069, by Venus.

The primary component, α Cancri A, is a white A-type main sequence dwarf with an apparent magnitude of +4.26. Its companion, α Cancri B, is an eleventh magnitude star. In the year 1836, its position angle was observed at 325 degrees with a separation from the main star α Cancri A of 11.3arcseconds. From studying its light curve during occultation, it is thought that α Cancri A may itself be a close binary, consisting of two stars with similar brightness and a separation of 0.1arcseconds.

The ābhāsa concept focuses on the essential nature of manifestation. In order to analyze in detail the nature of stuff (tattva - literally "that-ness") the Pratyabhijna system appropriated the 25 tattva ontology of Samkhya and improved on it by expanding the upper tattvas. Instead of Spirit (Purusha) and Nature (Prakriti), Kashmir Shaivism has five pure tattvas representing the Ultimate Reality and then six more representing the occultation process (māyāa) which translates the non-dual pure Reality to time and space limited world and its subjects.

John Bevis (10 November 1695 in Salisbury, Wiltshire - 6 November 1771) was an English doctor, electrical researcher and astronomer. He is best known for discovering the Crab Nebula in 1731. Bevis has also observed an occultation by Venus of Mercury on 28 May 1737 NS, (17 May 1737 OS) and observed and found a prediction rule for eclipses of Jupiter's moons. From observations made with his telescope at Stoke Newington, Middlesex, he compiled a star catalogue (more of an atlas) entitled Uranographia Britannica around 1750.

Retrieved on 2017-04-26. In 1813, he began to study astronomy under the mathematically inclined professor Carl Friedrich Gauss at the University of Göttingen, while Gauss was the director of the Göttingen Observatory. From there, he went to study with Carl Gauss's instructor, Johann Pfaff, at the University of Halle, where he completed his doctoral thesis The occultation of fixed stars in 1815. In 1816, he was appointed as Extraordinary Professor to the "chair of astronomy and higher mechanics" at the University of Leipzig.

Klio (minor planet designation: 84 Klio) is a fairly large and very dark main- belt asteroid. It was discovered by R. Luther on August 25, 1865, and named after Clio, the Muse of history in Greek mythology. The name Clio had previously been suggested by the discoverer of 12 Victoria, and that is the name B. A. Gould, editor of the prestigious Astronomical Journal, adopted for that asteroid, because of the controversy over the name Victoria. An occultation by Klio over a dim star was observed on April 2, 1997.

The satellite launched on a reused Falcon 9 rocket by SpaceX from Vandenberg Air Force Base, SLC-4E on 22 February 2018 at 14:17 UTC. The satellite hosted two secondary payloads: an AIS receiver and the Radio-Occultation and Heavy Precipitation (ROHP) experiment. The launch was shared by two SpaceX test satellites for their Starlink, named Tintin A and B. It was the final flight of a Block 3 first stage, and reused the booster B1038 from the Formosat-5 mission. Paz weighs , and its total mass with fuel is .

According to the survey carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's WISE telescope (WISE), Lyka measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0520 and a diameter of 27.89 km based on an absolute magnitude of 11.6. Further published mean-diameters by the WISE team include (), (), () and () with albedos between () and (). An asteroid occultation, observed on 4 March 2005, gave a best-fit ellipse dimension of 28.0 × 28.0 kilometers.

Some scholars, including Bernard LewisThe Assassins: A Radical Sect in Islam, Bernard Lewis, pp. 23, 35, 49. also point out, that the idea of an Imam in occultation was not new in 873 CE but that it was a recurring factor in Shia history. Examples of this include the cases of Muhammad ibn al-Hanafiyyah (according to the Kaysanites Shia), Muhammad al- Nafs al-Zakiyya, Musa al-Kadhim (according to the Waqifite Shia), Muhammad ibn Qasim (al-Alawi), Yahya ibn Umar and Muhammad ibn Ali al-Hadi (according to the Muhammadite Shia).

Both single and double ellipsoid models were fit to the data with both providing approximately the same goodness of fit; leaving the team unable to differentiate between a single elongated object and the contact binary model put forth by Kaasalainen et al. An observation of an occultation by 44 Nysa of TYC 6273-01033-1 from the Dutch amateur astronomer Harrie Rutten showed a two-phase reappearance on March 20, 2012. This confirms the conical shape or the binary nature of Nysa. In December 2006, Shepard et al.

Solar eclipses on Neptune occur when any of the natural satellites of Neptune pass in front of the Sun as seen from the planet. For bodies which appear smaller in angular diameter than the Sun, the proper term would be a transit and bodies which are larger than the apparent size of the Sun, the proper term would be an occultation. All of Neptune's inner moons and Triton can eclipse the Sun as seen from Neptune. All other satellites of Neptune are too small and/or too distant to produce an umbra.

The best local spherical approximation to the ellipsoid in the vicinity of a given point is the osculating sphere. Its radius equals the Gaussian radius of curvature as above, and its radial direction coincides with the ellipsoid normal direction. The center of the osculating sphere is offset from the center of the ellipsoid, but is at the center of curvature for the given point on the ellipsoid surface. This concept aids the interpretation of terrestrial and planetary radio occultation refraction measurements and in some navigation and surveillance applications.

162 Laurentia is a large and dark main-belt asteroid that was discovered by the French brothers Paul Henry and Prosper Henry on 21 April 1876, and named after Joseph Jean Pierre Laurent, an amateur astronomer who discovered asteroid 51 Nemausa. An occultation by Laurentia was observed from Clive, Alberta on 21 November 1999. Photometric observations of this asteroid from multiple observatories during 2007 gave a light curve with a period of 11.8686 ± 0.0004 hours and a brightness variation of 0.40 ± 0.05 in magnitude. This is in agreement with previous studies in 1994 and 2007.

It is believed by Twelver Shia and Alevi Muslims that the Twelve Imams have been foretold in the Hadith of the 12 accomplishers. All of the Imams met unnatural deaths, with the exception of the last Imam who, according to Twelver and Alevi belief, is living in occultation. Some of the Imams also have a leading role within some Sufi orders and are seen as the spiritual heads of Islam, because most of the Silsila (spiritual chain) of Sufi orders leads back to the Prophet through one of the Twelve Imams.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Piccolo measures between 26.92 and 28.02 kilometers in diameter and its surface has an albedo between 0.1538 and 0.199. In April 2003, an albedo of 0.131 and a diameter of 29.9 kilometers have also been deduced from a stellar occultation. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1447 and a diameter of 27.50 kilometers based on an absolute magnitude of 10.52.

In 2006, photometric observations obtained by David Higgins at Canberra, Australia, Donald Pray at Carbuncle Hill Observatory , as well as Peter Kušnirák and Petr Pravec at Ondřejov Observatory revealed that Okamoto is a synchronous binary asteroid with a minor-planet moon orbiting it every 20.32 hours at an estimated average distance of . The discovery was announced on 19 October 2006. The mutual occultation events indicated the presence of a satellite 25% the size of its primary, which translates into an estimated diameter of kilometers depending on the underlying size estimate of the primary.

He obtained a value of 3,800 km. Subsequent measurement attempts arrived at values ranging from 2,500 to 6,000 km, or from slightly smaller than the Moon (3,474.2 km) to nearly half the diameter of Earth. Data from the approach of Voyager 2 to Neptune on August 25, 1989, led to a more accurate estimate of Triton's diameter (2,706 km). In the 1990s, various observations from Earth were made of the limb of Triton using the occultation of nearby stars, which indicated the presence of an atmosphere and an exotic surface.

Lunar transits have been used to map X-ray emissions from the nebula. Before the launch of X-ray-observing satellites, such as the Chandra X-ray Observatory, X-ray observations generally had quite low angular resolution, but when the Moon passes in front of the nebula, its position is very accurately known, and so the variations in the nebula's brightness can be used to create maps of X-ray emission. When X-rays were first observed from the Crab Nebula, a lunar occultation was used to determine the exact location of their source.

Mausoleum of 1 st Wali–ul–Hind:Moulai Abadullah, Khambat, Gujarat, era 1050–1100 CE. Dawoodi Bohra 53rd Dai Syedna Mufaddal Saifuddin, with Dawat office at Mumbai. Bohra İsmayıllı Shia was established in Gujarat in the second half of the 11th century. This community's belief system originates in Yemen, evolved from the Fatimid were persecuted due to their adherence to Fatimid Shia Islam leading the shift of Dawoodi Bohra to India. After occultation of their 21st Fatimid Imam Tayyib, they follow Dai as representative of Imam which are continued till date.

The Shuckburgh, also called the "Eastern Equatorial" at the time Halley's comet was sometimes used with a micrometer microscope. For the observations of Halley's 1835, the Transit and Arnold 1 and 2 clocks were used. Observations were recorded in August, September, and October, but it could not view the comet after October 19th, because its view was blocked by another part of the observatory building. The Shuckburgh is also reported to have been used for observing the occultation of stars by the Moon and observing the moons of Jupiter.

Prior to the era of the Hubble Space Telescope and space probes reaching the outer Solar System, attempts to detect satellites around asteroids were limited to optical observations from Earth. For example, in 1978, stellar occultation observations were claimed as evidence of a satellite for the asteroid 532 Herculina. However, later more-detailed imaging by the Hubble Telescope did not reveal a satellite, and the current consensus is that Herculina does not have a significant satellite. There were other similar reports of asteroids having companions (usually referred to as satellites) in the following years.

The Spitzer Space Telescope estimated it to have a diameter of , while the Herschel Space Telescope estimated it to be . If the latter case is true, would be comparable in size to the dwarf planet , and would also be the largest Solar System object without a name . is one of the 10 largest TNOs currently known and large enough to be considered a dwarf planet under the 2006 draft proposal of the IAU. A stellar occultation by was observed on 26 July 2019 from British Columbia, with a single chord of 831 km.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Milller measures between 19.74 and 26.34 kilometers in diameter, and its surface has an albedo between 0.111 and 0.196. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1085 and a diameter of 24.31 kilometers with an absolute magnitude of 11.1. The asteroid was also involved in the asteroid occultation of a 10th magnitude star in the constellation Cancer in April 2004.

In Shia Islam, Jihad is one of the ten Practices of the Religion, (though not one of the five pillars). Traditionally, Twelver Shi'a doctrine has differed from that of Sunni Islam on the concept of jihad, with jihad being "seen as a lesser priority" in Shia theology and "armed activism" by Shias being "limited to a person's immediate geography". Shia doctrine teaches that offensive Jihad can only be carried out under the leadership of Mahdi, whom is believed to return from occultation. However, "struggles to defend Islam" are permissible before his return.

Agrippa (; ) was a Greek astronomer. The only thing that is known about him regards an astronomical observation that he made in 92 AD. Ptolemy writes that in the twelfth year of the reign of Domitian, on the seventh day of the Bithynian month Metrous, Agrippa observed the occultation of a part of the Pleiades by the southernmost part of the Moon. The purpose of Agrippa's observation was probably to check the precession of the equinoxes, which was discovered by Hipparchus. The lunar crater Agrippa is named after him.

Though the masses had not yet been adopted by the IAU. The ephemerides were created to support the arrivals of the MER and Cassini spacecraft. DE411See, for instance, which compares DE413 output with DE411. was widely cited in the astronomical community, but not publicly released by JPL DE412See, for instance, which references DE412. was widely cited in the astronomical community, but not publicly released by JPL DE413 was released in 2004 with updated ephemeris of Pluto in support of the occultation of a star by its satellite Charon on 11 Jul 2005.

He was proselytized and taught by the Isma'ili missionary (dā'ī) Abu Muhammad Abdan, the brother-in-law of Hamdan Qarmat, the overall leader of the Isma'ili movement in Iraq. In the period about 874/884, Abu Sa'id was then in turn sent as a dā'ī to proselytize in Fars, in the area of Jannaba, Siniz, Tawwaj, and Mahruban. His mission was successful, and he gathered converts and funds: all dā'īs were required to gather funds for the awaited mahdī, who was still in Occultation. Eventually, however, he was denounced to the Sunni authorities.

Calligraphic of the Wilayat al-Faqih. The Guardianship of the Islamic Jurist, also called the Governance of the Jurist (; ), is a post-Occultation theory in Shia Islam which holds that Islam gives a faqīh (Islamic jurist) custodianship over people. Ulama supporting the theory disagree over how encompassing custodianship should be. One interpretation – Limited Guardianship of the Islamic Jurist – holds that guardianship should be limited to non-litigious matters (al-omour al-hesbiah) including religious endowments (Waqf) judicial mattersInterview: Hamid al-Bayati (May 2003) and the property for which no specific person is responsible.

The thermosphere and upper part of the stratosphere contain a large concentration of ions and electrons, forming the ionosphere of Uranus. Radio occultation observations by the Voyager 2 spacecraft showed that the ionosphere lies between 1,000 and 10,000 km altitude and may include several narrow and dense layers between 1,000 and 3,500 km. The electron density in the Uranian ionosphere is on average , reaching to as high as in the narrow layers in the stratosphere. The ionosphere is mainly sustained by solar UV radiation and its density depends on the solar activity.

Radial velocity data was taken by HIRES at the Keck I telescope in order to determine the mass of the planet. Independently, observations were made with the Spitzer Space Telescope at infrared wavelengths of 3.6 and 4.5 micrometres. Along with additional data taken by Kepler, these observations detected the occultation and phase curves of Kepler-6b behind its star. The confirmation of Kepler-6b was announced at the 215th meeting of the American Astronomical Society with the discoveries of planets Kepler-4b, Kepler-5b, Kepler-7b, and Kepler-8b on January 4, 2010.

He was succeeded by his son, Muhammad at-Taqi (Ahmed ibn Abadullah).WAFI AHMAD (197-212/813-828) With the death of Ja'far al-Sadiq in 765 (148 AH), Isma'il in 775 (158 AH) and Muhammad in 813 (197 AH), the Isma'ili Imams were impelled to hide; this first occultation lasted from 813-882 (197-268 AH).Achilles des Souza, "Mediation in Islam - an Investigation" (Rome, 1975, p. 35) The eighth to tenth Ismaili Imams were hidden from the public because of threats from the Abbasid Caliphate and were known by their nicknames.

The size of Leleākūhonua depends on the assumed albedo (reflectivity); if it is a darker object then it would also have to be larger; a higher albedo would demand that it be smaller. The faint object has a visual magnitude of 24.64, comparable to the visual magnitudes of Pluto's smaller moons. It was initially estimated to be in diameter under the assumption of an albedo of 0.15, though observations of a single-chord stellar occultation at Penticton, Canada on 20 October 2018 suggested a smaller diameter of , corresponding to a higher albedo of 0.21.

Kepler-78b orbits around its parent star once every 8.5 hours. It reflects 20% to 60% of the starlight it receives. Transits and occultation of an Earth-sized planet in an 8.5-hour orbit Due to its extremely close solar orbit, which is about 40 times closer than Mercury is to the Sun, the planet's surface is estimated to be at a temperature of to . This temperature is high enough to have stripped the planet of any stable atmosphere, but the liquid and solid portions of the planet should be stable.

In October 2003, photometric observations of Shoemaker by Robert D. Stephens gave a long rotation period of 57.02 hours. After re-measuring the images with newer software and calibration techniques, two mutual occultation and eclipsing events were found, indicating that Shoemaker might be a synchronous binary asteroid with a minor-planet moon orbiting it every 55 hours. Observations in 2010, were difficult due to incomplete coverage and gave an orbital period of 27.39 hours for the secondary. Observations by astronomers at Etscorn Campus Observatory () in 2015, did not mention any mutual events.

In October 2013, photometric observations by Petr Pravec and a large international collaboration, revealed, that Shoko is an synchronous binary asteroid with a minor-planet moon orbiting it every 36.20 hours (1.508 days) at an estimated average distance of . The discovery was announced in December 2013. The mutual occultation events suggest the presence of a satellite with a diameter or more than 40% the size of its primary. The discoverers also suspect that there might be a possible third body, which would make it a rare trinary asteroid.

SPICAV: The "SPectroscopy for Investigation of Characteristics of the Atmosphere of Venus" (SPICAV) is an imaging spectrometer that was used for analyzing radiation in the infrared and ultraviolet wavelengths. It is derived from the SPICAM instrument flown on Mars Express. However, SPICAV has an additional channel known as SOIR (Solar Occultation at Infrared) that was used to observe the Sun through Venus's atmosphere in the infrared. VIRTIS: The "Visible and Infrared Thermal Imaging Spectrometer" (VIRTIS) is an imaging spectrometer that observes in the near-ultraviolet, visible, and infrared parts of the electromagnetic spectrum.

A second centaur, 2060 Chiron, is also suspected to have a pair of rings. Based on stellar-occultation data that were initially interpreted as resulting from jets associated with Chiron's comet-like activity, the rings are proposed to be 324 (± 10) km in radius. Their changing appearance at different viewing angles can explain the long-term variation in Chiron's brightness over time. Ring systems may form around centaurs when they are tidally disrupted in a close encounter (within 0.4 to 0.8 times the Roche limit) with a giant planet.

In November 2004, a rotational lightcurve of Engelhardt was obtained from photometric observations by American astronomer Brian Warner at this Palmer Divide Observatory in Colorado. Lightcurve analysis gave a well-defined rotation period of 3.066 hours with a brightness amplitude of 0.16 magnitude (). In December 2011, a follow-up observation by Warner gave a period of 3.0661 hours with 0.18 amplitude (). Due to a couple of supposed occultation and eclipsing events, Warner also suspects that Engelhardt might by a binary system with a minor- planet moon orbiting it every 36.03 hours.

Uthman ibn Sa'id al-Asadi al-Amri ( ') was the first of the Four Deputies of the twelfth Imam, Imam al-Mahdi in Twelver Shia Islam.The First Deputy of Imam Mahdi yjc.ir Retrieved 6 Oct 2018 He was appointed as an agent and deputy of Imam al-Mahdi while the Imam was in the Minor Occultation, a period in which he would only contact his followers through the Four Deputies. After ibn Sa'id's death, his son Abu Jafar Muhammad ibn Uthman was appointed as the second deputy by Hujjat-Allah al-Mahdi.

This index gradient causes refraction of light rays (at a shallow angle to the road) from the sky, bending them into the eye of the viewer, with their apparent location being the road's surface. The Earth's atmosphere acts as a GRIN lens, allowing observers to see the sun for a few minutes after it is actually below the horizon, and observers can also view stars that are below the horizon. This effect also allows for observation of electromagnetic signals from satellites after they have descended below the horizon, as in radio occultation measurements.

The telescope observed a drop of the hydrogen flux, which is explained by the occultation of the star by a gas stream falling towards the star. The system also shows an enhanced X-ray and ultraviolet flux with XMM- Newton data during periastron, which is an additional sign of stronger accretion during periastron. The orbital inclination of the binary and the inclination of the circumbinary disk is nearly the same. Any circumbinary planet that could form in this disk would orbit in the same plane as the binary.

Ellwood, p.119 According to Ellwood, > Those who see Eliade's fascination with the primordial as merely reactionary > in the ordinary political or religious sense of the word do not understand > the mature Eliade in a sufficiently radical way. [...] Tradition was not for > him exactly Burkean 'prescription' or sacred trust to be kept alive > generation after generation, for Eliade was fully aware that tradition, like > men and nations, lives only by changing and even occultation. The tack is > not to try fruitlessly to keep it unchanging, but to discover where it is > hiding.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide- field Infrared Survey Explorer (WISE), Ganymed measures between 31.66 and 37.67 kilometers in diameter and its surface has an albedo between 0.218 and 0.293. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2809 and a mean-diameter of 31.57 kilometers based on an absolute magnitude of 9.50. Carry published a diameter kilometers in 2012. An occultation of a star by Ganymed was observed from California on 22 August 1985.

According to astronomer Michael Brown, measures 615 kilometres in diameter, based on an absolute magnitude of 4.2, with an assumed albedo of 0.10, respectively. The Johnston's Archive claims a 770 km diameter, but does not state magnitude or albedo; if it is assumed to use the 3.8 magnitude given by the MPC and JPL (themselves without albedo estimates), this would correspond to an albedo of approx 0.092. On 25 February 2019, a stellar occultation by was observed in New Zealand. From these observations, a lower limit of 575 km was placed for its mean diameter.

Whipple would try to detect comet sized objects out to Visualization of hypothesized Oort cloud Whipple was a proposed space observatory in the NASA Discovery Program. The observatory would try to search for objects in the Kuiper belt and the theorized Oort cloud by conducting blind occultation observations. Although the Oort cloud was hypothized in the 1950s, it has not yet been directly observed. The mission would attempt to detect Oort cloud objects by scanning for brief moments where the objects would block the light of background stars.

Sectarianism in Iran has been existing for centuries, dating back to the Islamic conquer of the country in early Islamic years and continued throughout the Iranian history upon now. During the Safavid Dynasty's reign sectarianism started to play an important role in shaping the path of the country. During the Safavid rule between 1501 and 1722, Shiism started to evolve and became established as the official state religion, leading to the creation of the first religiously legitimate government since the occultation of the Twelfth imam. This pattern of sectarianism prevailed throughout the Iranian history.

The telescope The Bok Telescope was named after the prolific astronomer and director of Steward Observatory from 1966–1969, Bart Bok, one of the most beloved astronomers in Tucson. It was used on March 18, 2007 by Bruno Sicardy to view Pluto's occultation of a star in Sagittarius. The building itself features a very long spiral staircase leading to the telescope and a balcony called "The Bok Walk". In the 2010s the Bok telescope helped support a survey with KNPO telescopes in preparation for the DESI instrument on the 4-m Mayall telescope.

Paul O. Wennberg is the R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering at the California Institute of Technology (Caltech). He is the director of the Ronald and Maxine Linde Center for Global Environmental Science. He is chair of the Total Carbon Column Observing Network and a founding member of the Orbiting Carbon Observatory project, which created NASA's first spacecraft for analysis of carbon dioxide in the atmosphere. He is also the principal investigator for the Mars Atmospheric Trace Molecule Occultation Spectrometer (MATMOS) to investigate trace gases in Mars's atmosphere.

With more sensitive instruments than its predecessor Mariner 2, Mariner 5 was able to shed new light on the hot, cloud-covered planet and on conditions in interplanetary space. Radio occultation data from Mariner 5 helped to understand the temperature and pressure data returned by the Venera 4 lander, which arrived at Venus shortly before it. After these missions, it was clear that Venus had a very hot surface and an atmosphere even denser than expected. The operations of Mariner 5 ended in November 1967 and it is now defunct in a heliocentric orbit.

Nadir and Occultation for MArs Discovery (NOMAD) is a 3-channel spectrometer on board the ExoMars Trace Gas Orbiter (TGO) launched to Mars orbit on 14 March 2016. NOMAD is designed to perform high-sensitivity orbital identification of atmospheric components, concentration and temperature, their sources, loss, and cycles. It measures the sunlight reflected from the surface and atmosphere of Mars, and it analyses its wavelength spectrum to identify the components of the Martian atmosphere that may suggest a biological source. The Principal Investigator is Ann Carine Vandaele, from the Belgian Institute for Space Aeronomy, Belgium.

Raj`a () in Islamic terminology, refers to the Second Coming, or the return to life of a given past historical figure after that person's physical death. Shia believe that before the Day of Judgement, Muhammad al-Mahdi will return with a group of chosen companions. This return is more properly known as zuhur or 'appearance,' as the Hidden Imam is believed to have remained alive during his period of occultation, since the year 874. The return of these historical figures will signify the beginning of the Last Judgment.

Radio occultation is a remote sensing technique where a GNSS signal tangentially scrapes the Earth, passing through the atmosphere, and is received by a Low Earth Orbit (LEO) satellite. As the signal passes through the atmosphere, it is refracted, curved and delayed. An LEO satellite samples the total electron content and bending angle of many such signal paths as it watches the GNSS satellite rise or set behind the Earth. Using an Inverse Abel's transform, a radial profile of refractivity at that tangent point on earth can be reconstructed.

Lachesis (minor planet designation: 120 Lachesis) is a large main-belt asteroid. It was discovered by French astronomer Alphonse Borrelly on April 10, 1872, and independently by German-American astronomer Christian Heinrich Friedrich Peters on April 11, 1872, then named after Lachesis, one of the Moirai, or Fates, in Greek mythology. A Lachesean occultation of a star occurred in 1999 and was confirmed visually by five observers and once photoelectrically, with the chords yielding an estimated elliptical cross- section of . Photometric observations of this asteroid were made in early 2009 at the Organ Mesa Observatory in Las Cruces, New Mexico.

The word "transit" refers to cases where the nearer object appears smaller than the more distant object. Cases where the nearer object appears larger and completely hides the more distant object are known as occultations. In astronomy, planetary transits and occultations occur when a planet passes in front of another object, as seen by an observer. The occulted object may be a distant star, but in rare cases it may be another planet, in which case the event is called a mutual planetary occultation or mutual planetary transit, depending on the relative apparent diameters of the objects.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Annika measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2062 and a diameter of 22.20 kilometers based on an absolute magnitude of 10.6. Alternative mean-diameter measurements published by the WISE team include (), (), () and () with corresponding albedos of (), (), () and (). On 26 August 2010, an asteroid occultation of Annika gave a best-fit ellipse dimension of ().

According to the surveys carried out by the Japanese Akari satellite, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Infrared Astronomical Satellite IRAS, Altona measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0356 and a diameter of 80.85 kilometers based on an absolute magnitude of 9.7. Alternative mean-diameter measurements published by the WISE team include (), (), () and () with corresponding albedos of (), (), (), and (). An asteroid occultation observed on 3 April 2008, gave a best-fit ellipse dimension of ().

According to the survey carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Rosalinde measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.0931 and calculates a diameter of 18.75 kilometers based on an absolute magnitude of 11.83. Alternative mean-diameter measurements published by the WISE team include (), () and () with corresponding albedos of (), () and (). On 7 June 2015, an asteroid occultation gave a best-fit ellipse dimension of 19.0 × 19.0 kilometers.

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Infrared Astronomical Satellite IRAS, and the Japanese Akari satellite, Imhilde measures (), () and () kilometers in diameter and its surface has a low albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0476 and a diameter of 48.39 km based on an absolute magnitude of 10.5. Further published mean-diameters and albedos by the WISE team include () and () and albedos of () and (). An asteroid occultation observed on 8 November 2011, gave a best-fit ellipse dimension of 49.0 × 49.0 kilometers.

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the Infrared Astronomical Satellite IRAS, and the Japanese Akari satellite, Amelia measures , and kilometers in diameter and its surface has an albedo of , and , respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1183 and a diameter of 50.94 kilometers based on an absolute magnitude of 9.4. An asteroid occultation, observed on 2 November 2006, gave a best-fit ellipse dimension of 51.0 × 51.0 kilometers. These timed observations are taken when the asteroid passes in front of a distant star.

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Infrared Astronomical Satellite IRAS, and the Japanese Akari satellite, Jovita measures (), () and () kilometers in diameter and its surface has a low albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.0670 and a diameter of 58.95 km based on an absolute magnitude of 9.7. Alternative mean- diameters published by the WISE team include (), (), () and () with albedos between 0.048 and 0.069. An asteroid occultation, observed on 5 February 2007, gave a best-fit ellipse dimension of 58.0 × 58.0 kilometers.

According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Japanese Akari satellite, and the Infrared Astronomical Satellite IRAS, Arne measures , and kilometers in diameter, and its surface has an albedo of , and , respectively. Other published measurements by the WISE team also includes mean-diameters of , and with corresponding albedos of , , and . The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0258 and a diameter of 57.20 km based on an absolute magnitude of 10.8. An asteroid occultation on 3 February 2015, gave a best-fit ellipse dimension of 53.0 × 53.0 kilometers.

According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Infrared Astronomical Satellite IRAS, and the Japanese Akari satellite, Petunia measures , and kilometers in diameter, and its surface has an albedo of , and , respectively. An additional measurement published by the WISE team gives an alternative mean-diameter of . The Collaborative Asteroid Lightcurve Link adopts the WISE results revised by Pravec, that is an albedo of 0.1654 and a diameter of 29.12 km based on an absolute magnitude of 10.25. An asteroid occultation on 30 September 2014, gave a best-fit ellipse dimension of ().

According to the surveys carried out by the Japanese Akari satellite, the Infrared Astronomical Satellite IRAS, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Benjamina measures , and kilometers in diameter with an albedo of its surface of , and , respectively. Additional measurements by the WISE telescope were published giving a mean- diameter as low as , and as high as . The Collaborative Asteroid Lightcurve Link adopts the result from IRAS, that is, an albedo of 0.0559 and a diameter of 80.53 kilometers based on an absolute magnitude of 9.22. The asteroid had been observed in 7 stellar occultation events since 2003.

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Infrared Astronomical Satellite IRAS, and the Japanese Akari satellite, Rockefellia measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0357 and calculates a diameter of 58.51 kilometers based on an absolute magnitude of 10.4. Alternative mean-diameter measurements published by the WISE team include (), (), () and () with corresponding albedos of (), () and () and (). On 13 May 2005, an asteroid occultation gave a best-fit ellipse dimension of 59.0 × 59.0 kilometers.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Agamemnon measures between 131.04 and 185.30 kilometers in diameter, based on a common absolute magnitude of 7.89 and a surface albedo between 0.037 and 0.072. A concurring diameter estimate of kilometers from an occultation event (see below) has also been obtained. The Collaborative Asteroid Lightcurve Link agrees with the results obtained by IRAS, that is, an albedo of 0.0444 and a diameter of 166.66 kilometers based on an absolute magnitude of 7.89.

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE) and the Japanese Akari satellite, Hooveria measures () and () kilometers in diameter and its surface has an albedo of () and (), respectively. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.20 and calculates a diameter of 29.72 km based on an absolute magnitude of 10.00. Further published mean-diameters and albedos by the WISE team include (), (), () and () with corresponding albedos of (), (), (), and (). An asteroid occultation on 1 February 2006, gave a best-fit ellipse dimension of 33.0 × 33.0 kilometers.

According to the survey carried out by the Japanese Akari satellite, the Infrared Astronomical Satellite IRAS, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Kunigunde measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0792 and a diameter of 39.29 km based on an absolute magnitude of 10.4. Further published mean-diameters and albedos by the WISE team include () and () with corresponding albedos of () and (). An asteroid occultation on 21 November 2004, gave a best-fit ellipse dimension of 39.0 × 39.0 kilometers.

But Shias would still benefit from the Imam because belief in his hidden presence keeps them from committing evil in their life. Since Shias believe that the primordial light of the prophethood has continued to shine through the ages in the character of the Imams, be they hidden or apparent, no idea ever rose regarding the inaccessibility of the Hidden Imam in the state of occultation. According to Baha'i scholar Moojan Momen, numerous stories exist of the Hidden Imam "manifesting himself to prominent members of the ulama (Muslim religious scholars)."Momen, Moojan, An Introduction to Shi'i Islam, Yale University Press, 1985, p.

458/1066) had noted that some Sufi gnostics (djamaʿa min ahl al-kashf) agreed with the Twelver doctrine about the identity of the Mahdi and his ghaybah (occultation). The Persian Sufi Sadr al- Din Ibrahim al-Hammuyi (late 7th/13th century) supported Twelver doctrine on the Mahdi in his Faraʾid al-simtayn. The Egyptian Sufi al-Shaʿrani, while generally showing no sympathy for Shiʿism, affirmed in his al-Yawaḳit wa ʾl- dj̲awahir (written in 958/1551) that the Mahdi was a son of Imam al-Hasan al- ʿAskari, born in the year 255/869, and would remain alive until his meeting with Jesus.

Manwë and Thorondor were expected to go through a period of mutual occultations and transits from 2014–2018, where one object crosses in front of the other as seen from Earth. Pluto and Charon went through a similar series of mutual events from 1985–1990. Observations of these events could allow for better estimates of the radii of the two objects and their densities, as well as possibly determining their shapes and mapping surface color and albedo features. The first event, an inferior occultation, is predicted for 2014 July 16, and they continue until 2018 October 25.

165 Loreley is a main-belt asteroid that was discovered by C. H. F. Peters on August 9, 1876, in Clinton, New York and named after the Lorelei, a figure in German folklore. In the late 1990s, a network of astronomers worldwide gathered light curve data that was ultimately used to derive the spin states and shape models of 10 new asteroids, including (165) Loreley. The light curve of this asteroid varies by no more than 0.2 in magnitude, while the derived shape model shows multiple flat spots on the surface. One stellar occultation by Loreley has been observed, on July 20, 2003.

Abū Shuʿayb Muḥammad ibn Nuṣayr al-Numayri () was a disciple of the tenth Twelver Imam, Ali al‐Hadi and of the eleventh Twelver Imam, Hasan al‐Askari, and founder of the Alawites. Ibn Nusayr was known to his followers as a representative (Bab) of al‐Askari and of the twelfth Twelver Imam, Hujjat- Allah al-Mahdi during the Minor Occultation. A rival of his in claiming to be the bāb (door) to the Imams was Abu Yaqub Ishaq, founder of the Ishaqiyya. The followers of Ibn Nusayr are known as the NusayrisEncyclopedia Iranica, "NOṢAYRIS" () or, since the 1920s, the Alawis ().

In April and May 2006, Bridges was observed by astronomers David Higgins at Hunters Hill Observatory (), Australia, Petr Pravec and Peter Kušnirák at Ondřejov Observatory Czech Republic, Walter R. Cooney Jr., John Gross and Dirk Terrell at Sonoita Research Observatory (), United States, and Robert Stephens at Santana Observatory , United States. The observed mutual occultation/eclipsing events revealed, that Bridges is a binary asteroid, that is orbited every hours by a minor-planet moon. A refined orbital period of 16.317 hours was later published. Based on the system's secondary-to-primary mean-diameter ratio of , the satellite measures approximately kilometers in diameter.

The densities and rock–ice fractions are known for only a small number of objects for which the diameters and the masses have been determined. The diameter can be determined by imaging with a high-resolution telescope such as the Hubble Space Telescope, by the timing of an occultation when an object passes in front of a star or, most commonly, by using the albedo of an object calculated from its infrared emissions. The masses are determined using the semi-major axes and periods of satellites, which are therefore known only for a few binary objects.

The Akhbaris (, ) are Twelver Shia Muslims who reject the use of reasoning in deriving verdicts, and believe in Quran and Hadith. The term Akhbari (from khabara, news or report) is usually used in contrast to Usuli (from Uṣūl al- fiqh, principles of Islamic jurisprudence). Unlike Usulis, Akhbaris do not follow or do Taqleed of a Mujtahid, the marja‘s (models for imitation) who practice modern form of ijtihad (independent legal reasoning); consequently they do not accept Usul al-fiqh. Akhbaris perform Taqleed of Imam Muhammad al- Mahdi the Twelfth Imam of Shias who is in the Occultation.

As early as the 5th century AH / 11th century CE, more than 150 years after the Occultation of the 12th Imām, Shaykhu t-Ta'ifa reinterpreted the doctrine to allow delegation of the Imām's judicial authority to those who had studied fiqh. Although he implies in his writings that this function should only be undertaken by the ulama if there is no one else to do it. Shaykhu t-Taifa considered the ulamā' the best agents of the donor to distribute religious taxes since they knew to whom it should be distributed. Nevertheless, individuals were free to do this themselves if they wished.

Between September 2001, and February 2003, photometric observations of Celle were obtained with the 1.8-meter Vatican Advanced Technology Telescope on Mount Graham, Arizona, by American astronomers William Ryan at New Mexico Tech and NMHU in collaboration with Carlos Martinez and Lacey Stewart as part of a larger survey. The mutual occultation events revealed that Celle is an asynchronous binary asteroid with a minor-planet moon orbiting it every 36.57 hours (1.52 days) at an average distance of . The discovery was announced on 3 May 2003. The satellite measures approximately or 43% the size of its primary.

Zeta Geminorum has been reported to be a spectroscopic binary on the basis of lunar occultation observations, but this has not been confirmed by other methods. Zeta Geminorum's primary (WDS J07041+2034 Aa) is a Classical Cepheid variable that undergoes regular, periodic variation in brightness because of radial pulsations. In the V band, the apparent magnitude varies between a high of 3.68 and a low of 4.16 (with a mean of 3.93) over a period of 10.148 days. This period of variation is decreasing at the rate of 3.1 seconds per year, or 0.085 seconds per cycle.

This is a double-lined spectroscopic binary system, having a circular orbit with a period of 2.5 days. It was discovered to be variable independently by Friedrich Schwab and Heinrich Van Solowiew in 1913. Both components are metallic-lined, or Am stars, with a spectrum showing a deficiency of calcium and scandium, and an overabundance of heavier elements. Together they form an EA, or Algol-type, eclipsing binary with the primary occultation reducing the net magnitude to a minimum of 6.54 and the secondary eclipse lowering it to 6.43, over a cycle time of 2.52501936 days.

The exocomets can be detected by spectroscopy as they transit their host stars. The transits of exocomets, like the transits of exoplanets, produce variations in the light received from the star. Changes are observed in the absorption lines of the stellar spectrum: the occultation of the star by the gas cloud coming from the exocomet produces additional absorption features beyond those normally seen in that star, like those observed in the ionized calcium lines. As the comet comes close enough to the star, cometary gas is evolved from the evaporation of volatile ices and dust with it.

The effect is most pronounced when the radiation traverses a long atmospheric limb path. At radio frequencies the amount of bending cannot be measured directly; instead the bending can be calculated using the Doppler shift of the signal given the geometry of the emitter and receiver. The amount of bending can be related to the refractive index by using an Abel transform on the formula relating bending angle to refractivity. In the case of the neutral atmosphere (below the ionosphere) information on the atmosphere's temperature, pressure and water vapour content can be derived giving radio occultation data applications in meteorology.

The session was recorded at Parr Street Studios, Liverpool and engineered by Rich Turvey of The Wild Swans, who also played guitar and keyboards. Stuart Mann played drums on the recording, which was issued by Occultation in November 2010. The following summer, and following some geographically-challenged songwriting, Perrin and Finney alongside Arash Torabi (The June Brides), Mike Kellie (Spooky Tooth / The Only Ones) together with producer Nick Halliwell (The Granite Shore) entered a studio in Exeter. Four days later, they had cut the basic tracks for a new Distractions album; at that time simply entitled '2'.

The δ ring consists of two components: a narrow optically dense component and a broad inward shoulder with low optical depth. The width of the narrow component is 4.1–6.1 km and the equivalent depth is about 2.2 km, which corresponds to a normal optical depth of about 0.3–0.6. The ring's broad component is about 10–12 km wide and its equivalent depth is close to 0.3 km, indicating a low normal optical depth of 3 × 10−2. This is known only from occultation data because Voyager 2's imaging experiment failed to resolve the δ ring.

For 7 March 2017, a stellar occultation by Orcus had been predicted to take place in the Americas and over the Pacific Ocean. Observations were made at five sites in North and South America, and two solid body chords have been observed. Using speckle imaging, the occulted star was revealed to be a close double star, and a reconstruction of the orbits of Orcus and Vanth showed that both chords were from Vanth (occulting either of the two stars) rather than Orcus. A non-detection at a nearby site placed a constraint of () on the diameter of Vanth.

For example, if the Moon passes into the shadow of Earth and disappears from view, this event is called a lunar eclipse. If the visible disk of the nearer object is considerably smaller than that of the farther object, the event is called a transit. When Mercury passes in front of the Sun, it is a transit of Mercury, and when Venus passes in front of the Sun, it is a transit of Venus. When the nearer object appears larger than the farther one, it will completely obscure its smaller companion; this is called an occultation.

Born in Dundee, he was educated at the High School of Dundee, after which he trained as a lawyer, working his way up through the profession as an assistant to a variety of nobles. However, his major hobbies were astronomy and mathematics, and after coming up with a new method for using lunar occultation to measure longitude he came to the attention of Thomas Young, superintendent of the Royal Navy's "Nautical Almanac". Young helped the young Henderson enter the larger world of astronomical science, and on his death a posthumous letter recommended to the Admiralty that Henderson take his place.

Since the last Imam, Muhammad al-Mahdi, went into "occultation" in 939 and is not expected back until end times, this left Shi'a without religiously sanctioned governance. The first Shi'a regime, the Safavid dynasty in Iran, propagated the Twelver faith, made Twelver's law the law of the land, and patronized Twelver scholarship. For this, Twelver ulema "crafted a new theory of government" which held that while "not truly legitimate", the Safavid monarchy would be "blessed as the most desirable form of government during the period of awaiting" for Muhammad al-Mahdi, the twelfth imam.Nasr, Vali, The Shia Revival, Norton, (2006), pp.

Abu Jafar Muhammad ibn Uthman (, ') was the second of the Four DeputiesMuhammad ibn UthmanIbn Saeed Omri ashoora.ir Retrieved 6 Oct 2018 of the Minor Occultation after death of Uthman ibn Sa'id al-Asadi, his father and the first deputy. According to Twelver Shia Islam, the twelfth Imam, Hujjat- Allah al-Mahdi, appointed Abu Jafar as his second deputy. He was Imam al- Mahdi's deputy until from 257 AH until his death in 304 or 305 AH. After his death, Abul Qasim Husayn ibn Ruh al-Nawbakhti was appointed as the third deputy of Imam al-Mahdi.

Abu al-Qasim al-Husayn ibn Ruh Nawbakhti (, ', died 937 or 938 AD) was the third of the Four Deputies appointed by the twelfth Imam of Twelver Shias, Hujjat-Allah al-Mahdi during the Minor Occultation. He was a native of Qum who migrated to Baghdad during the time of Uthman ibn Sa'id al-Asadi, the first deputy. Al‑Nawbakhti was a companion of the second deputy Abu Jafar Muhammad ibn Uthman and became his agent for several years. After the death of al- Nawbakhti, Abul Hasan Ali ibn Muhammad al-Samarri was appointed as the fourth deputy of Hujjat-Allah al-Mahdi.

Infrographic of Alice data from its 2015 encounter with Pluto on New Horizons Alice is an ultraviolet imaging spectrometer for spacecraft, with one used on the New Horizons spacecraft, and another on the Rosetta spacecraft. Alice is a small telescope with spectrograph and a special detector with 32 pixels each with 1024 spectral channels detecting ultraviolet light. Alice has an off-axis telescope which sends light to a Rowland-circle spectrograph, and the instrument has a field of view of 6 degrees. It is designed to capture airglow and solar occultation at the same time, and has two inputs to allow this.

Persecutions started forty days after the disappearance into Occultation of al-Hakim, who was thought to have been converting people to the Unitarian faith for over twenty years prior. Al-Hakim convinced some heretical followers such as al-Darazi of his soteriological divinity and officially declared the Divine call after issuing a decree promoting religious freedom. The call summoned people to a true unitarian belief that removed all attributes (wise, just, outside, inside, etc.) from God. It promoted absolute monotheism and the concepts of supporting your fellow man, true speech and pursuit of oneness with God.

Perspective, relative size, occultation and texture gradients all contribute to the three-dimensional appearance of this photo. Depth perception is the visual ability to perceive the world in three dimensions (3D) and the distance of an object. Depth sensation is the corresponding term for animals, since although it is known that animals can sense the distance of an object (because of their ability to move accurately, or to respond consistently, according to that distance), it is not known whether they perceive it in the same subjective way that humans do. Depth perception arises from a variety of depth cues.

According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the Japanese Akari satellite, and the Infrared Astronomical Satellite IRAS, Massinga measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2392 and a diameter of 71.47 kilometers based on an absolute magnitude of 7.9. On 29 February 2012, an asteroid occultation of Massinga gave a best-fit ellipse dimension of (), with a high quality rating of 3. These timed observations are taken when the asteroid passes in front of a distant star.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer and the Japanese Akari satellite, Gedania measures , and kilometers in diameter and its surface has an albedo of , and , respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0754 and a diameter of 58.18 kilometers based on an absolute magnitude of 9.6. An alternative mean-diameter measurement published by the WISE team gave () with corresponding albedo of (). On 5 February 2006, an asteroid occultation of Gedania gave a best-fit ellipse dimension of (), with a poor quality rating of 1.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Harvard measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2051 and a diameter of 16.89 kilometers based on an absolute magnitude of 11.2. An asteroid occultation observed on 25 May 2003, gave a best-fit ellipse dimension of () with a low quality rating of 1. These timed observations are taken when the asteroid passes in front of a distant star.

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Hildburg measures () and () kilometers in diameter and its surface has an albedo of () and (), respectively. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a stony asteroid of 0.20 and derives a diameter of 19.28 kilometers based on an absolute magnitude of 10.94. The WISE team also published an alternative mean-diameter () and an albedo of (). On 23 August 2004, an asteroid occultation gave a best-fit ellipse dimension of () with a low quality rating of 1.

This is a spectroscopic binary star system with an orbital period of around 3.6 years and an eccentricity of 0.5. It is classified as a probable (91% chance) eclipsing binary with the variable star designation UZ Lyn, showing a net magnitude decrease of 0.3 during an occultation. The primary component is an A-type main-sequence star with a stellar classification of A2 Vs, where the 's' indicates narrow (sharp) absorption lines. The orbiting companion may be the source of the X-ray emission from this system, as stars similar to the primary component do not generally produce detectable levels of X-rays.

The ORT has produced results on radio galaxies, quasars, supernovae and pulsars, One long-term program determined the angular structure of several hundred distant radio galaxies and quasars using the lunar occultation method. The application of this database to observational cosmology provided independent evidence against the steady state theory and supported the Big Bang model of the universe. The telescope is currently being used mainly to observe interplanetary scintillation, which may provide valuable information about the solar wind and magnetic storms that affect the near-Earth environment. Interplanetary scintillation observations provide a database to understand space weather changes and their predictability.

MFI was previously known as "RAGS International" until the year 2002, when Younus AlGohar became the CEO and formally established the organisation. At this time, AlGohar also formed MFI's sister organisation, Kalki Avatar Foundation, under the apparent guidance of Shahi. After Shahi's disappearance in 2001, Shahi's followers in the MFI declared it to be akin to miraculous occultation and continued their activities under the leadership of AlGohar, who they claim is the personally appointed representative of Shahi. In June 2018, Shahi's daughter, Farah Naz, expressed her support of the MFI and was appointed the role of 'Guardian' of the MFI.

From 1951 until 1953, he served as an astronomy research assistant at Dearborn Observatory. While a student at Northwestern, he met his future wife, Elizabeth Strong—the couple were married in 1952. In 1953 he joined the military in the U.S. Army Map Service Lunar Occultation Program, serving until 1955 whereupon he returned to the study of astronomy at the University of California, Berkeley. As a doctoral student, he was awarded the Dorothy Klumpke Roberts Prize in Astronomy by the Astronomical Society of the Pacific during 1956, and was a Lick Observatory Fellow for 1957−58.

A number of such events occurred in 2007–2008, including an occultation of Ariel by Umbriel on 19 August 2007. Currently Ariel is not involved in any orbital resonance with other Uranian satellites. In the past, however, it may have been in a 5:3 resonance with Miranda, which could have been partially responsible for the heating of that moon (although the maximum heating attributable to a former 1:3 resonance of Umbriel with Miranda was likely about three times greater). Ariel may have once been locked in the 4:1 resonance with Titania, from which it later escaped.

Two proposed methods depend on the relative motions of the moon and a star or planet. An appulse is the least apparent distance between the two objects, an occultation occurs when the star or planet passes behind the moon — essentially a type of eclipse. The times of either of these events can be used as the measure of absolute time in the same way as with a lunar eclipse. Edmond Halley described the use of this method to determine the longitude of Balasore, using observations of the star Aldebaran (the Bull's Eye) in 1680, with an error of just over half a degree.

Spectrometers on the satellite can map the distribution of CO2 particles across the planet by measuring the average amount of CO2 above specific locations. Wennberg is the principal investigator for the development of the Mars Atmospheric Trace Molecule Occultation Spectrometer (MATMOS), a collaboration between Caltech and the Canadian Space Agency with NASA support. MATMOS will be flown on the ExoMars Trace Gas Orbiter and take spectra of the sunlight through Mars' atmosphere as the spacecraft goes through its orbital sunrise and sunset. MATMOS will be able to measure trace gases in Mars's atmosphere at a concentrations of parts per trillion.

After the birth of the child, Hasan al-Askari revealed the child to his forty close followers and then the child was hidden. According to Kohlberg, after the death of Hasan al-Askari, some Shia followers believed he was the Qa'im and Hujjat-Allah Mahdi was not his son, alleging he did not have any child. Also, the group believed that he had not died and had gone into occultation. Another part of historians studying the pedigrees of some Central Asian "shejere" saints, believe that the 12th Imam was not the only son of Imam Hasan al-Askari.

James McMahon is an American amateur astronomer, acknowledged for his visual observations of asteroid occultations. In 1978 his observation of the occultation of the asteroid 532 Herculina with the star SAO 120774, together with photometric study made at the Lowell Observatory, was considered a proof of the existence of a Herculina's natural satellite, which would be the first discovery of an asteroid moon in history. However, a 1993 Hubble Space Telescope observation failed to confirm the discovery. In 1979 James McMahon was the first person awarded with the newly established Amateur Achievement Award of the Astronomical Society of the Pacific.

Ate (minor planet designation: 111 Ate) is a main-belt asteroid that was discovered by the German-American astronomer C. H. F. Peters on August 14, 1870, and named after Ate, the goddess of mischief and destruction in Greek mythology. In the Tholen classification system, it is categorized as a carbonaceous C-type asteroid, while the Bus asteroid taxonomy system lists it as an Ch asteroid. Two stellar occultations by Ate were observed in 2000, only two months apart. The occultation of the star HIP 2559 by 111 Ate was used to determine a chord length of 125.6 ± 7.2 km through the asteroid, giving a lower bound on the maximum dimension.

Amalthea is thought to be a fragment from the mantle of a Vesta-sized, 300–600 km diameter parent body that broke up around one billion years ago, with the other major remnant being 9 Metis. The spectrum of Amalthea reveals the presence of the mineral olivine, a relative rarity in the asteroid belt. Based on observations made during a stellar occultation by Amalthea of a 10th- magnitude star on 14 March 2017, it was announced in July 2017 that the asteroid has a small, 5-kilometer-sized satellite, provisionally designated S/2017 (113) 1. The observations also indicated that Amalthea has a distinctly elongated shape.

The name signifies that it was the 273rd object (ordered by right ascension) of the Third Cambridge Catalog of Radio Sources (3C), published in 1959. After accurate positions were obtained using lunar occultation by Cyril Hazard at the Parkes Radio Telescope, the radio source was quickly associated with an optical counterpart, an unresolved stellar object. In 1963, Maarten Schmidt and Bev Oke published a pair of papers in Nature reporting that 3C 273 has a substantial redshift of 0.158, placing it several billion light-years away. Prior to the discovery of 3C 273, several other radio sources had been associated with optical counterparts, the first being 3C 48.

While the Soviet Union initially claimed the craft reached the surface intact, re-analysis including atmospheric occultation data from the American Mariner 5 spacecraft that flew by Venus the day after its arrival demonstrated that Venus's surface pressure was 75-100 atmospheres, much higher than Venera 4's 25 atm hull strength, and the claim was retracted. Realizing the ships would be crushed before reaching the surface, the Soviets launched Venera 5 and Venera 6 as atmospheric probes. Designed to jettison nearly half their payload prior to entering the planet's atmosphere, these craft recorded 53 and 51 minutes of data, respectively, while slowly descending by parachute before their batteries failed.

According to the survey carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Gunhild measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0656 and a diameter of 51.89 kilometers based on an absolute magnitude of 10.0. Alternative mean-diameter measurements published by the WISE team include (), () and () with corresponding albedos of (), () and (). Several asteroid occultation observed between 2010 and 2014 gave a best-fit ellipse dimension of 52.0 × 52.0 kilometers (one observation) and 63.0 × 63.0 kilometers (three observations).

According to the survey carried out by the Japanese Akari satellite, the Infrared Astronomical Satellite IRAS, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Leopoldina measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0497 and a diameter of 76.14 kilometers based on an absolute magnitude of 9.47. Alternative mean-diameter measurements published by the WISE team include (), (), (), () and () with albedos in the range of 0.049 to 0.06. Three asteroid occultation were obtained on 29 January 1996, 30 August 2010 and 16 May 2015.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Picka measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of and a diameter of 46.72 kilometers based on an absolute magnitude of 9.4. On 13 May 2015, an asteroid occultation of Picka gave a best-fit ellipse dimension of (), which is similar to that obtained by the Japanese Akari satellite. These timed observations are taken when the asteroid passes in front of a distant star.

According to the survey carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Ratisbona measures (), () and () kilometers in diameter and its surface has a very low albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts the results from IRAS, that is, a albedo of 0.0591 and a diameter of 67.57 km based on an absolute magnitude of 9.54. Further published mean-diameters and albedos by the WISE team include () and () and albedos of () and (). An asteroid occultation, observed on 13 September 2014, gave a best-fit ellipse dimension of 78.0 × 78.0 kilometers.

According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Infrared Astronomical Satellite IRAS, and the Japanese Akari satellite, Asplinda measures , and kilometers in diameter, and its surface has an albedo of , and , respectively. Another published measurement by the WISE team also gives a mean-diameters of with corresponding albedo of . The Collaborative Asteroid Lightcurve Link adopts the results from IRAS, that is, an albedo of 0.0415 and a diameter of 47.08 km based on an absolute magnitude of 10.71. An asteroid occultation on 15 August 2006, gave a best-fit ellipse dimension of 47.0 × 47.0 kilometers.

According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Japanese Akari satellite, and the Infrared Astronomical Satellite IRAS, Leocadia measures , and kilometers in diameter, and its surface has a very low albedo of , and , respectively. Additional measurements by the WISE telescope were published giving a mean-diameter as low as . The Collaborative Asteroid Lightcurve Link adopts the result from IRAS, that is, an albedo of 0.0435 and a diameter of 19.51 kilometers based on an absolute magnitude of 9.22. An asteroid occultation on 19 August 2013, gave a best-fit ellipse dimension of 19.0 × 19.0 kilometers.

According to the survey carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide- field Infrared Survey Explorer, Philippa measures between 65.4 and 65.9 kilometers in diameter and its surface has an albedo between 0.05 and 0.06. The Collaborative Asteroid Lightcurve Link adopts the results from IRAS, that is, an albedo of 0.0555 and a diameter of 65.67 kilometers based on an absolute magnitude of 9.67. In April 2014, Philippa was also subject to an asteroid occultation, timed observations when the asteroid passes in front of a distant star. The measurements gave an estimated diameter of 65 kilometers.

According to the survey carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Rhoda measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0560 and calculates a diameter of 62.73 kilometers based on an absolute magnitude of 10.74. Alternative mean-diameter measurements published by the WISE team include in ascending order (), (), () and () and albedos of (), (), () and (). An asteroid occultation, observed on 23 March 2009, gave a best-fit ellipse dimension of 63.0 × 63.0 kilometers.

According to the survey carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Anneliese measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0505 and a diameter of 46.98 kilometers based on an absolute magnitude of 10.5, while Alvares gives a diameter of () and an albedo of (). An asteroid occultation, observed on 14 September 2012, gave a best-fit ellipse dimension of 48.0 × 48.0 kilometers. These timed observations are taken when the asteroid passes in front of a distant star.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Begonia measures , and kilometers in diameter, and its surface has an albedo of , and , respectively. The Collaborative Asteroid Lightcurve Link adopts the results from IRAS, that is, an albedo of 0.0456 and a diameter of 69.21 km based on an absolute magnitude of 9.77. Further published mean-diameters and albedos by he WISE team include , , and with corresponding albedos of , , and . An asteroid occultation on 25 March 2005, gave a best-fit ellipse dimension of 69.0 × 69.0 kilometers.

It was first discovered by Harold J. Reitsema, William B. Hubbard, Larry A. Lebofsky and David J. Tholen, based on fortuitous ground-based stellar occultation observations on May 24, 1981, given the temporary designation S/1981 N 1 and announced on May 29, 1981. The moon was recovered and confirmed to be the only object in its orbit during the Voyager 2 flyby in 1989 after which it received the additional designation S/1989 N 2 on August 2, 1989. The announcement by Stephen P. Synnott spoke of “10 frames taken over 5 days”, which gives a recovery date sometime before July 28. The name was given on September 16, 1991.

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, ' measures 66.23 and 68.50 kilometers in diameter and its surface has an albedo of 0.044 and 0.042, respectively. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and consequently calculates a shorter diameter (due to the higher albedo) of 58.29 kilometers using an absolute magnitude of 9.9. In September 2005, an observed asteroid occultation gave an inconclusive cross-section of (no fit, but observations sufficiently reliable to derive an astrometric position of the asteroid relative to the star).

In March 2008, a lightcurve of Kiuchi was obtained from photometric observations by astronomers Peter Kušnirák and Petr Pravec at Ondřejov Observatory in the Czech Republic, by Julian Oey at Leura Observatory, Australia, by Robert Stephens at Goat Mountain, California, by Mark Husárik at Skalnaté pleso Observatory, Slovakia, and by Judit Györgyey Ries at McDonald Observatory, Texas. These photometric observations revealed, that Kiuchi is a synchronous binary asteroid with a minor-planet moon orbiting it every 20.90 hours based on mutual eclipsing and occultation events. The satellite's diameter is about a third of that of Kiuchi, which translates into 1.3 kilometers (secondary-to-primary mean-diameter ratio of ).

In the second half of the twentieth century Alan Cousins set up very precise southern standards for UBV and introduced a widely used system of VRI photometry that enjoyed international recognition for precision. In 1977 the occultation of the star SAO 158687 was observed by Joseph Churms from the former Royal Observatory and these observations provided needed confirmation of the Uranian rings discovered from the Kuiper aeroplane by Elliot et al. During the 19th century the Observatory was regarded as the main advisor to the colonial government on scientific matters. it served as the repository for standard weights and measures of the Colony and was responsible for timekeeping and geodetic surveying.

The only physical property directly derivable to that of the central star, which follows from the amount of occultation of stellar light during a transit. This ratio was measured to be 0.021, giving a planetary radius of 1.11±0.14 times that of Earth. The planet is about 11% larger in radius than Earth (between 4.5% smaller and 26.5% larger), giving a volume about 1.37 times that of Earth (between 0.87 and 2.03 times as large). A very wide range of possible masses can be calculated by combining the radius with densities derived from the possible types of matter from which planets can be made.

149, 2008. The texts provide formidable insight into the incorporation of the Universal Intellect and Soul of the world in 11th century Egypt, when the deity showed itself to men through Fatimid Caliph al-Hakim and his doctrines. These display a notable form of Arabic Neoplatonism blended with Ismailism and adopted Christian elements of great interest for the philosophy and history of religions. It is believed by the Druze from interpretation of the epistles that Al-Hakim did not die, but merely withdrew into occultation and will return one day and reveal the Druze wisdom to the world in order to inaugurate a golden age.

Edmund Halley communicated to the Royal Society his phase- determinations of the total solar eclipse of 3 May 1715. On 14 July 1715 Pound observed an occultation of a star by Jupiter, on 30 October an eclipse of the moon, and made, in 1716 and 1717, various planetary observations all with a fifteen-foot telescope. Huygens's 123-foot focal length object-glass, lent to Pound in 1717 by the Royal Society, was mounted by him in the grounds of Wanstead House on the maypole just removed from the Strand, and procured for the purpose by Sir Isaac Newton. The inconveniences of this instrument were commented upon by Joseph Crosthwait.

Absolute values of surface pressure are difficult to obtain from occultation data, because this data does not usually reach the lowest layers of the atmosphere. So, surface pressure has to be extrapolated, and this is somewhat ambiguous due to the height dependence of temperature and, consequently, pressure not being completely clear . The radius of Pluto must also be known, but it was poorly constrained before 2015. So, precise values of Pluto's surface pressure were impossible to calculate in previous times. For some occultations since 1988, pressure was calculated for a reference level of from the center of Pluto (which later turned out to be 88±4 km from the surface).

Upon leaving Care, Simpson re-formed the Wild Swans and released two albums Bringing Home the Ashes (1988, Sire) and Space Flower (1990, Sire). Space Flower reunited Broudie and Simpson, with Broudie producing the album and playing guitar. Simpson performed under the moniker Skyray from 1996 to 2006; he re-formed again the Wild Swans in 2008, releasing a new album, The Coldest Winter for a Hundred Years (2011, Occultation Recordings). Ian Broudie went on to form the Lightning Seeds in the late 1980s, releasing a string of albums which spawned hit singles like "Pure", "Change", "Sugarcoated Iceberg", "The Life of Riley" and "You Showed Me".

Within the Twelver Shi’i legal tradition, the fourth source for deriving legal principles is not qiyās but rather the intellect ’’'Aql’’. Twelver Shi’a regard the ulama (scholars) as authorities in legal and religious matters during the Occultation (ghayba) of the Imamah Mahdi. Until the return of the hidden Imam, it is the responsibility of the ulāma’ to be his deputies and provide guidance on worldly matters. In modern interpretations of Twelver Shi’ism, the most revered and learned scholars are styled as references for emulation (marja taqlīd). This system of deriving legal principles effectively replaces both the Sunni notion of consensus (ijmā’) and deductive analogy (qiyās)Elhadj, Elie.

A pair of Voyager 2 images of Neptune's ring system The first mention of rings around Neptune dates back to 1846 when William Lassell, the discoverer of Neptune's largest moon, Triton, thought he had seen a ring around the planet. However, his claim was never confirmed and it is likely that it was an observational artifact. The first reliable detection of a ring was made in 1968 by stellar occultation, although that result would go unnoticed until 1977 when the rings of Uranus were discovered. Soon after the Uranus discovery, a team from Villanova University led by Harold J. Reitsema began searching for rings around Neptune.

This, along with the prospect of other objects of similar size being discovered in the future, motivated the International Astronomical Union (IAU) to define the term planet for the first time. Under the IAU definition approved on August 24, 2006, Eris is a "dwarf planet," along with objects such as Pluto, Ceres, Haumea and Makemake, thereby reducing the number of known planets in the Solar System to eight, the same as before Pluto's discovery in 1930. Observations of a stellar occultation by Eris in 2010 showed that it was very slightly smaller than Pluto, which was measured by New Horizons as in July 2015.

Aryabhata accurately calculated the Earth's circumference as 24,835 miles, which was only 0.2% smaller than the actual value of 24,902 miles. Aryabhatta was the first to prepare the Indian Almanac, better known as panchangam. Rural amateur astronomers still use the panchang, while some assist the pandits in drafting the annual almanac. Indian amateur astronomers use maps that, depending on experience and intentions, may range from simple planispheres through detailed maps of very specific areas of the night sky for getting involved in projects like photographing the whole sky, the Messier objects or observing the occultation of the stars by the Moon, or studying asteroids.

This figure was widely expected—not just among the Shi'a—to be a descendant of Ali. Among Shi'a, however, this belief became a core tenet of their faith, and was applied to several Shi'a leaders who were killed or died; their followers believed that they had gone into "occultation" () and would return (or be resurrected) at the appointed time. These traditions manifested themselves in the succession of the sixth imam, Ja'far al-Sadiq. Al-Sadiq had appointed his son Isma'il ibn Ja'far as his successor, but Isma'il died before his father, and when al-Sadiq himself died in 765, the succession was left open.

Shrine of Al- Askari The city is also home to al-Askari Shrine, containing the mausolea of the Imams Ali al-Hadi and Hasan al-Askari, the tenth and eleventh Shiʿi Imams, respectively, as well as the place from where Muhammad al-Mahdi, known as the "Hidden Imam", reportedly went into The Occultation in the belief of the Twelver or Shias. This has made it an important pilgrimage centre for the Imami Shias. In addition, Hakimah and Narjis, female relatives of the Prophet Muhammad and the Imams, held in high esteem by Muslims, are buried there, making this mosque one of the most significant sites of worship.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide- field Infrared Survey Explorer (WISE), Vinifera measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. Alternative mean-diameter measurements published by the WISE team include (), (), () and () with corresponding albedos of (), (), () and (). The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0500 and a diameter of 45.07 kilometers based on an absolute magnitude of 10.6. On 13 January 2002, an asteroid occultation of Vinifera gave a best-fit ellipse dimension of (), with a quality rating of 2.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Marlu measures (), () and () kilometers in diameter and its surface has a low albedo of ), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts an albedo of 0.0431 and derives a diameter of 69.87 kilometers based on an absolute magnitude of 9.81. The WISE-team also published two alternative mean-diameters of () and () with a corresponding albedo of () and (). An asteroid occultation on 1 May 1985, gave a best-fit ellipse dimension of () with an intermediate quality rating of 2.

According to the surveys carried out by the Japanese Akari satellite, the Infrared Astronomical Satellite IRAS, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Gutemberga measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0494 and a diameter of 65.57 kilometers based on an absolute magnitude of 9.8. Alternative mean-diameter measurements published by the WISE team include () and () with corresponding albedos of () and (). On 27 June 2008, an asteroid occultation of Gutemberga gave a best-fit ellipse dimension of (), with a poor quality rating of 1.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Nina measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-albedo of 0.1694 and takes a diameter of 77.46 kilometers based on an absolute magnitude of 8.1. The WISE team also published an alternative mean-diameter of () with an albedo of (). On 10 November 2005, an asteroid occultation of Nina gave a best-fit ellipse dimension of (), with a quality rating of 2.

According to the surveys carried out by the NEOWISE mission of NASA's Wide- field Infrared Survey Explorer (WISE), the Japanese Akari satellite, and the Infrared Astronomical Satellite IRAS, Nora measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0404 and a diameter of 39.84 kilometers based on an absolute magnitude of 11.1. Alternative mean-diameter measurements published by the WISE team include (), (), (), () and () with corresponding albedos of (), (), (), () and (). On 4 May 2004, an asteroid occultation of Nora gave a best-fit ellipse dimension of (), with a poor quality rating of 1.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Melanie measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts the albedo obtained by IRAS and derives a diameter of 41.38 kilometers using an absolute magnitude of 10.59. Alternative mean-diameters published by the WISE team include (), (), (), () and () with a corresponding albedo of (), (), (), () and (). On 4 August 2002, an asteroid occultation gave a best-fit ellipse dimension of () with a low quality rating of 0.

Ayatollah Khomeini was a senior Islamic jurist cleric of Shia (Twelvers) Islam. Shia theology holds that Wilayah or Islamic leadership belongs to divinely-appointed line of Shia Imams descended from the Prophet Muhammad, the last of which is the 12th Imam, Muhammad al- Mahdi. The God-given (Infallible) knowledge and sense of justice of the Imams makes them the definitive reference for (Shia) Muslims in every aspect of life, religious or otherwise, including governance. However, the twelfth Imam disappeared into what Shia believe is "occultation" (ghaybat) in 939 AD and so has not been present to rule over the Muslim community for over a thousand years.

Zoeb bin Moosa (d.546 AH/1151 CE) was the first Dai-ul-Mutlaq, and lived and died in Haus, Yemen. Tayyibis (which include the Dawoodi Bohra) believe the second and current period of occultation (satr) began after Imam Tayyeb went into seclusion and Imam from his progeny is very much present as Mahdi on earth every time. The Nizari Ismailis maintain that the Shi'a Ismaili Imams and Ismaili Muslim thinkers have explained that al-Mahdi is not a single person but actually a function undertaken by some of the hereditary Shi'a Ismaili Imams from the progeny of Prophet Muhammad and Imam 'Ali ibn Abi Talib.

The estimated age is 1.6 billion years. It has an apparent visual magnitude of +3.53, allowing it to be seen with the naked eye. It is 0.18 degree south of the ecliptic so it is occasionally occulted by the Moon and, rarely, by a planet; and is eclipsed by the sun from about 10-12 July.In the Sky Earth astronomy reference utility showing the ecliptic and relevant date as at J2000 - present Thus the star can be viewed the whole night, crossing the sky, in mid-January. The last occultation by a planet was by Saturn on June 30, 1857, and the next will be by Venus on August 12, 2420.

Four first magnitude stars, Regulus, Spica, Antares, and Aldebaran, are sufficiently close to the ecliptic that they may be occulted by the Moon. In addition, two star clusters visible to the naked eye, the Beehive Cluster and the Pleiades, are often occulted. Depending on one's location on the Earth, there are usually several occultations involving naked eye objects every year and many more that can be observed using binoculars or a telescope. Accurate timings (accuracy at least +/-0.02 seconds) of lunar occultations are scientifically useful in fields such as lunar topography, astrometry, and binary star studies and are collected by the International Occultation Timing Association - IOTA.

The Waqifites believed in the Mahdism and the occultation of Imam Mūsà ibn Ja‘far al-Kāẓim. They believed Musa was alive, did not die, and would never die, that he was raised to heaven just as Jesus was raised, and that he was the awaited one who would fill the world with justice and fairness as it was filled with oppression and tyranny.The Waqifites' and Their Doctrines However, they later differed amongst themselves concerning Musa’s death and split into four sub-groups. Three of the sub-groups believed that Musa had died, while the other remaining sub-group persistently denied that Musa al-Kadhim had died.

Harold James Reitsema (born 1948) is an American astronomer who was part of the teams that discovered Larissa, the fifth of Neptune's known moons, and Telesto, Saturn's thirteenth moon. Reitsema and his colleagues discovered the moons through ground-based telescopic observations. Using a coronagraphic imaging system with one of the first charge-coupled devices available for astronomical use, they first observed Telesto on April 8, 1980, just two months after being one of the first groups to observe Janus, also a moon of Saturn. Reitsema, as part of a different team of astronomers, observed Larissa on May 24, 1981, by watching the occultation of a star by the Neptune system.

According to fellow astronomer Edward S. Holden, Peters deliberately chose a name from the Bible so as to annoy an overly pious theology professor of his acquaintance. Initially classified as a D-type asteroid, it was later classed as C-type based upon a broad absorption feature below 4,000 Å, most likely due to phyllosilicates on the surface. An occultation of the star HIP 37136 by 102 Miriam on February 15, 2000 was observed from multiple stations, with the chords yielding an estimated elliptical cross-section of . Photometric observations of this asteroid during 2007 at the Organ Mesa Observatory in Las Cruces, New Mexico, were used to create a light curve plot.

The next time a mutual planetary transit or occultation will happen (as seen from Earth) will be on 22 November 2065 at about 12:43 UTC, when Venus near superior conjunction (with an angular diameter of 10.6") will transit in front of Jupiter (with an angular diameter of 30.9"); however, this will take place only 8° west of the Sun, and will therefore not be visible to the unaided/unprotected eye. Before transiting Jupiter, Venus will occult Jupiter's moon Ganymede at around 11:24 UTC as seen from some southernmost parts of Earth. Parallax will cause actual observed times to vary by a few minutes, depending on the precise location of the observer.

Because the Moon's orbit around Earth is inclined by about 5.145° (5° 9') to the orbit of Earth around the Sun, eclipses do not occur at every full and new moon. For an eclipse to occur, the Moon must be near the intersection of the two orbital planes. The periodicity and recurrence of eclipses of the Sun by the Moon, and of the Moon by Earth, is described by the saros, which has a period of approximately 18 years. Because the Moon continuously blocks the view of a half-degree-wide circular area of the sky, the related phenomenon of occultation occurs when a bright star or planet passes behind the Moon and is occulted: hidden from view.

According to Twelvers, there is at all times an Imam of the era who is the divinely appointed authority on all matters of faith and law in the Muslim community. Ali was the first of the Twelve Imams, and, in the Twelvers view, the rightful successor to Muhammad, followed by male descendants of Muhammad through his daughter Fatimah. Each Imam was the son of the previous Imam, with the exception of Husayn ibn Ali, who was the brother of Hasan ibn Ali. The twelfth and final Imam is Muhammad al-Mahdi, who is believed by the Twelvers to be currently alive, and hidden in the Major Occultation until he returns to bring justice to the world.

The Druze believe the imam Al-Hakim bi-Amr Allah went into the Occultation after he disappeared in 1021 followed by the four founding Da'i of the Druze sect including Hamza ibn-'Ali ibn-Ahmad leaving the leadership to a fifth leader called Baha Al-Din. The Druze refused to acknowledge the successor of Al-Hakim as an Imam but accepted him as a Caliph.The Druzes: An Annotated Bibliography by Samy Swayd, Kirkland WA USA: ISES Publications(1998). . The faith further split from Ismailism as it developed unique doctrines which often classes it separately from both Ismailism and Islam, these include the belief that Al-Hakim bi-Amr Allah was God incarnate.

According to Twelvers, there is always an Imam of the era, who is the divinely appointed authority on all matters of faith and law in the Muslim community. Ali was the first of the Twelve Imams, and, in the Twelvers and Sufis' view, the rightful successor to Muhammad, followed by male descendants of Muhammad through his daughter Fatimah. Each Imam was the son of the previous Imam, with the exception of Husayn ibn Ali, who was the brother of Hasan ibn Ali. The twelfth and final Imam is Muhammad al-Mahdi, who is believed by the Twelvers to be currently alive, and hidden in the Major Occultation until he returns to bring justice to the world.

Within Shia Islam (Shiism), the various sects came into being because they differed over their Imams' successions, just as the Shia – Sunni separation within Islam itself had come into being from the dispute that had arisen over the succession to Muhammad. Each succession dispute brought forth a different tariqah (literal meaning 'path'; extended meaning 'sect') within Shia Islam. Each Shia tariqah followed its own particular Imam's dynasty, thus resulting in different numbers of Imams for each particular Shia tariqah. When the dynastic line of the separating successor Imam ended with no heir to succeed him, then either he (the last Imam) or his unborn successor was believed to have gone into concealment, that is, The Occultation.

Print gave a broader range of readers access to knowledge and enabled later generations to build directly on the intellectual achievements of earlier ones without the changes arising within verbal traditions. Print, according to Acton in his 1895 lecture On the Study of History, gave "assurance that the work of the Renaissance would last, that what was written would be accessible to all, that such an occultation of knowledge and ideas as had depressed the Middle Ages would never recur, that not an idea would be lost". Bookprinting in the 16th century Print was instrumental in changing the social nature of reading. Elizabeth Eisenstein identifies two long-term effects of the invention of printing.

Diagram showing Yinghuo-1's intended approach pathway to Mars. Following its transit to Mars, Yinghuo-1 was planned to separate from Fobos-Grunt in October 2012 and enter a 72.8-hour equatorial Martian orbit, with an orbital inclination of approximately 5 degrees. Fobos-Grunt and Yinghuo-1 would have conducted Mars ionosphere occultation experiments together, although Fobos-Grunt's primary objective was to obtain surface samples from the Martian moon Phobos. Yinghuo-1 would have experienced periods of up to 8.8 hours in darkness when its orbit carried it over Mars' nightside; it would have run on battery power during these periods, as its solar panels would have been unusable without direct sunlight.

The NASA Scatterometer (NSCAT), developed with the Jet Propulsion Laboratory, used fan-beam Doppler signals to measure wind speeds over bodies of water. The Total Ozone Mapping Spectrometer (TOMS) was built by CNES to study changes to Earth's ozone layer. The Polarization and Directionality of the Earth's Reflectance (POLDER) device was also developed by CNES, and was also launched on ADEOS II. The Improved Limb Atmospheric Spectrometer (ILAS) was developed by NASDA and the Environment Agency of Japan, and used grating spectrometers to measure the properties of trace gases using solar occultation. The Retroreflector in Space (RIS) and Interferometric Monitor for Greenhouse Gases (IMG) were both developed by Japan, and studied atmospheric trace gases and greenhouse gases respectively.

"Jupiter was the regal 'star' that conferred kingships - a power that was amplified when Jupiter was in close conjunctions with the Moon. The second occultation on April 17 coincided precisely when Jupiter was 'in the east', a condition mentioned twice in the biblical account about the Star of Bethlehem." In 3–2 BC, there was a series of seven conjunctions, including three between Jupiter and Regulus and a strikingly close conjunction between Jupiter and Venus near Regulus on June 17, 2 BC. "The fusion of two planets would have been a rare and awe-inspiring event", according to Roger Sinnott.Sinnott, Roger, "Thoughts on the Star of Bethlehem", Sky and Telescope, December 1968, pp. 384–386.

The first X-ray surveys of the sky in the Southern Hemisphere were provided by Skylark launches. It was also used with high precision in September and October 1972 in an effort to locate the optical counterpart of X-ray source GX3+1 by lunar occultation. In 1975, The Federal Republic of Germany through the DFVLR (now German Aerospace Center or DLR) agreed with Australia to launch a Skylark rocket at Woomera for scientific purposes.“Exchange of Notes constituting an Agreement between the Government of Australia and the Government of the Federal Republic of Germany concerning the Launching of a Skylark Vehicle and Payload at Woomera for Scientific Purposes. ATS 6 of 1975”.

One portion went to the descendants of Muhammad, the other portion was divided equally with one part given to Imam and clergy, while the other part went to the orphaned and poor Muslims.John L. Esposito (2004), The Oxford Dictionary of Islam, Oxford University Press, , p. 174 The famous view of contemporary Faqihs is that the Imam's portion (during the Occultation (Islam)) is used in the fields that the Marja' Taqlid has outlined. The Imam would use it in those ways, such as reinforcing Islam and Seminary, promotion of Islam, building mosques in necessary situations, libraries and schools' affairs, assisting old people, and actually all blessing affairs in the order of their priority and their religious significance.

Evidence suggesting a recent origin of the C ring has been gathered by researchers analyzing data from the Cassini Titan Radar Mapper, which focused on analyzing the proportion of rocky silicates within this ring. If much of this material was contributed by a recently disrupted centaur or moon, the age of this ring could be on the order of 100 million years or less. On the other hand, if the material came primarily from micrometeoroid influx, the age would be closer to a billion years. The Cassini UVIS team, led by Larry Esposito, used stellar occultation to discover 13 objects, ranging from 27 m to 10 km across, within the F ring.

Using a coronagraphic imaging system with one of the first charge-coupled devices available for astronomical use, they first observed Telesto in April 1980, just two months after being one of the first groups to observe Janus, also a moon of Saturn. Reitsema, as part of a different team of astronomers, observed Larissa in May 1981, by watching the occultation of a star by the Neptune system. Reitsema is also responsible for several advances in the use of false-color techniques applied to astronomical images. Reitsema was a member of the Halley Multicolour Camera team on the European Space Agency Giotto spacecraft that took close-up images of Comet Halley in 1986.

The Malwiya minaret at the Great Mosque of Samarra Saladin Governorate contains a number of important religious and cultural sites. Samarra, the governorate's largest city, is home to both the Al-Askari Shrine (an important religious site in Shia Islam where the 10th and 11th Shia Imams are buried), the Sardab where the 12th Imam al-Mahdi went into occultation, and the Great Mosque of Samarra with its distinctive Malwiya minaret. Samarra was also the capital of the Abbasid Caliphate in the 9th century CE, and today Abbasid Samarra is a UNESCO World Heritage Site. The ancient Neo-Assyrian Empire Assyrian city of Assur is located in Al-Shirqat District on the banks of the Tigris River.

Another group took up the ideas of the Waqifites. Another argued that, as a childless Imam cannot die and leave the world without imam, Imam Hasan al-Askari, therefore, had not died but had gone into occultation. As for Ja'far, the son of the tenth Imam, who claimed to be Imam after the death of his brother, Hasan al-Askari, was followed by a group of Shia who scattered soon, as Ja'far himself gave up his claim afterwards. Except the Zaidiyyah and the Isma'ilism which continue to exist until now, all other sects which were separated from the majority of twelver Shia, went extinct within a short period, with the Zaydis and Isma'ilis becoming a small minority.

SCISAT passes through the Earth's shadow 15 times per day, profiting from the occultation of the Sun to make a spectrographic analysis of the structure and chemistry of those parts of the upper atmosphere that are too high to be reached by balloons and airplanes and too low to be visited by orbiting satellites. This kind of analysis can help understand the depletion of the ozone layer and other upper atmosphere phenomena. SCISAT was placed in low Earth orbit, or LEO, by a Pegasus rocket launched from a NASA Lockheed L-1011 carrier aircraft on August 12, 2003 from Vandenberg Air Force Base. Expected to operate for two to five years, it was still operational in 2018.

Twelver theology, which mainly consists of five principles, has formed over the course of history on the basis of the teachings of Quran, and hadiths from Muhammad and the Twelve Imams (especially Jafar al-Sadiq), and in response to the intellectual movements in the Muslim world and major events of the Twelver history, such as the Battle of Karbala and the occultation of the twelfth Imam, Muhammad al-Mahdi. Mystics, philosophers, and traditional scholars all have diverse opinions about the unity of God, free will, and judgment day, as stated by Jafaar Seedaan.Our way in intellectual debates, by Jafaar Seedaan, p. 10. Care has been taken to mention the tradition view first then mention other views objectively.

Sayyed Radhi ud-Deen Ali ibn Musa ibn Tawus al Hasani wal Husaini (1193-1266 AD) commonly called Sayyed Ibn Tawus (Arabic: سید ابن طاووس) was a Shiite jurist, theologian, historian and astrologer. He was a descendant of Hasan ibn Ali through his father and a descendant of Husain ibn Ali through his mother. It is said that he met the twelfth Shiite imam, Muhammad al-Mahdi (869-present), who according to Shiites is living in occultation. He is known for his library and his numerous works which are still available in their original form and help us learn about the interests of Muslim scholars at the end of the Abbasid era.

Some Druze and non-Druze scholars like Samy Swayd and Sami Makarem state that this confusion is due to confusion about the role of the early preacher al-Darazi, whose teachings the Druze rejected as heretical. These sources assert that al-Hakim rejected al- Darazi's claims of divinity, and ordered the elimination of his movement while supporting that of Hamza ibn Ali. Al-Hakim disappeared one night while out on his evening ride – presumably assassinated, perhaps at the behest of his formidable elder sister Sitt al-Mulk. The Druze believe he went into Occultation with Hamza ibn Ali and three other prominent preachers, leaving the care of the "Unitarian missionary movement" to a new leader, al-Muqtana Baha'uddin.

According to the surveys carried out by the Japanese Akari satellite, the Infrared Astronomical Satellite IRAS, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Faïna measures (), () and () kilometers in diameter and its surface has a low albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts the results from IRAS, that is, an albedo of 0.0497 and a diameter of 110.50 kilometers based on an absolute magnitude of 8.66. The WISE team also published several alternative mean-diameters of (), (), (), () and (), with a corresponding albedo of (), (), (), (), and (). On 28 March 2007, an asteroid occultation of Faïna gave a best-fit ellipse dimension of () with a quality rating of 2, indicating its irregular, elongated shape.

According to the surveys carried out by the Japanese Akari satellite, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Infrared Astronomical Satellite IRAS, Ani measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0329 and a diameter of 103.52 kilometers based on an absolute magnitude of 9.25. Alternative mean-diameter measurements published by the WISE team include (), (), () and () with corresponding albedos of (), (), () and (). On 7 April 2000, an asteroid occultation of Ani gave a best-fit ellipse dimension of () with a good quality rating of 3.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Fini measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-data, that is an albedo of 0.0553 and a diameter of 62.56 kilometers based on an absolute magnitude of 9.78. Alternative mean-diameter measurements published by the WISE team include (), (), (), () and () with corresponding albedos of (), (), (), () and (). On 11 November 2006, an asteroid occultation of Fini gave a best-fit ellipse dimension of () with a low quality rating of 1.

Radhi ud-Deen Ali ibn Musa ibn Tawus (1193–1266 AD), often called Sayyed Ibn Tawus (Arabic: سید ابن طاووس), was a Shia jurist, theologian and historian. He was descended from Hasan ibn Ali through his father and from Husayn ibn Ali through his mother. It is said that he met the twelfth Shia Imam, Muhammad al-Mahdi (869–941), who, according to Shia belief, was or is living in occultation. Ibn Tawus is known for his library and his numerous works, which are still available in their original form and are considered good sources for learning about the concerns and teachings of Muslim scholars at the end of the Abbasid era.

However, at this point the Ismāʿīlī Imāms according to the Nizari and Musta'li found areas where they would be able to be safe from the recently founded Abbasid Caliphate, which had defeated and seized control from the Umayyads in 750 CE. During the period of Ja'far, the Abbasid Caliphate replaced the Umayyads and began to aggressively oppose belief in an Imamate. Due to strong suppression by the Abbasids, the seventh Ismāʿīlī Imam, Muhammad ibn Ismail, went into a period of occultation. During this period his representative, the Dāʿī, maintained the community. The names of the eighth, ninth, and tenth Imams are considered by some traditions to be "hidden", known only by their nicknames due to threats from the Abbasids.

The exact identity of that seventh imam was disputed, but by the late 9th century had commonly been identified with Muhammad, son of Isma'il and grandson of al-Sadiq. From Muhammad's father, Isma'il, the sect receives its name of "Isma'ili". Neither Isma'il's nor Muhammad's lives are well known, and after Muhammad's death during the reign of Harun al-Rashid (), the history of the early Isma'ili movement becomes obscure. Both the Twelvers and the Seveners held that their final imams were not dead, but had simply gone into hiding ("occultation"), and that they would soon return as a messiah, a mahdī ("the Rightly Guided One") or qāʾīm ("He Who Arises"), to usher in the end times.

Mu¹ Scorpii is an eclipsing binary of the Beta Lyrae type. Discovered to be a spectroscopic binary by Solon Irving Bailey in 1896, it was only the third such eclipsing pair to be discovered. This is a semidetached binary system where the secondary is close to filling its Roche lobe, or it may even be overflowing. The two stars revolve each other along a circular orbit with the components separated by 12.9 times the Sun's radius. Due to occultation of each component by the other, the apparent magnitude of the system decreased by 0.3 and 0.4 magnitudes over the course of the binary's orbit, which takes 34 hours 42.6 minutes to complete.

The existence of a ring system around a minor planet was unexpected because it had been thought that rings could only be stable around much more massive bodies. Ring systems around minor bodies had not previously been discovered despite the search for them through direct imaging and stellar occultation techniques. Chariklo's rings should disperse over a period of at most a few million years, so either they are very young, or they are actively contained by shepherd moons with a mass comparable to that of the rings. The team nicknamed the rings Oiapoque (the inner, more substantial ring) and Chuí (the outer ring), after the two rivers that form the northern and southern coastal borders of Brazil.

Mariner 3 (together with Mariner 4 known as Mariner-Mars 1964) was one of two identical deep-space probes designed and built by the Jet Propulsion Laboratory (JPL) for NASA's Mariner-Mars 1964 project that were intended to conduct close-up (flyby) scientific observations of the planet Mars and transmit information on interplanetary space and the space surrounding Mars, televised images of the Martian surface and radio occultation data of spacecraft signals as affected by the Martian atmosphere back to Earth. Although the launch was initially successful, there was a separation issue and Mariner 3 stopped responding when its batteries ran out of power. It was the third of ten spacecraft within the Mariner program.

The dome and minarets were repaired and the mosque reopened in April 2009. The 10th and 11th Shī'ite Imams, 'Alī al-Hādī ("an-Naqī") and his son Hasan al-'Askarī, known as al-'Askariyyayn ("the two 'Askarīs"), are buried in the shrine. Housed in the mosque are also the tombs of Hakimah Khātūn, sister of 'Alī al-Hādī; and Narjis Khātūn, the mother of Muħammad al- Mahdī.Shrine of Imām al-Hādī and Imām al-‘Askarī (ArchNet Digital Library) Adjacent to the mosque is another domed commemorative building, the Serdab ("cistern"), built over the cistern where the Twelfth Imam, Muħammad al-Mahdī, first entered the Minor Occultation or "hidden from the view"—whence the other title of the Mahdi, the Hidden Imam.

Lightcurve-based 3D-model of Kovacia In February 2008, a rotational lightcurve of Kovacia was obtained from photometric observations by a collaboration of French and Italian amateur astronomers including René Roy, Silvano Casulli, François Colas, Arnaud Leroy, Federico Manzini, Christophe Demeautis and Jean-François Coliac. Lightcurve analysis gave a well-defined rotation period of hours with a high brightness variation of magnitude, indicative of a non-spherical, elongated shape (). The result supersedes a previous observation by Roberto Crippa and Federico Manzini at the Sozzago Astronomical Station from November 2006, that determined a lower limit of 6 hours (). Due to observed mutual occultation and eclipsing events, the collaboration of astronomers strongly suspect Kovacia to be a binary asteroid with a satellite orbiting it every days.

Hujjat Allah ibn al-Hasan al-Mahdi (, ') is believed by the Twelver Shia to be the Mahdi, an eschatological redeemer of Islam and the final Imam of the Twelve Imams who will emerge with Isa (Jesus Christ) in order to fulfil their mission of bringing peace and justice to the world. Twelver Shias believe that al-Mahdi was born on the 15th Sha'ban 869 CE/ 255 AH and assumed Imamate at nearly 5 years of age following the killing of his father Hasan al-Askari. In the early years of his Imamah, he is believed to have had contact with his followers only through The Four Deputies. This period was known as the Minor Occultation () and lasted from 873–941 CE.The Return of al-Mahdi.

P11 A few days before the death of his fourth deputy Abu al-Hasan Ali ibn Muhammad al- Samarri in 941, he is believed to have sent his followers a letter. In that letter, which was transmitted by al-Samarri, he declared the beginning of Major Occultation (), during which Mahdi was not to be in contact with his followers directly, but had instructed them to follow the pious high clerics for whom he has mentioned some distinguishing merits. Most Sunni Muslims reject that he was the Mahdi and believe that the Mahdi has not yet been born. They believe his exact identity is only known to Allah, other than the idea that he is to be from the descendants of Muhammad.

During Brian Warner's initial photometric observation in February 2010 – carried out in collaboration with mentor Alan W. Harris at the Space Science Institute in La Canada, California, Petr Pravec at Ondřejov Observatory in the Czech Republic, and Joseph T. Pollock at Appalachian State University, North Carolina – it was revealed that Jedicke is a synchronous binary system with a minor-planet moon orbiting it every 16.7 hours. Based on the observed mutual eclipse/occultation events, the satellite diameter measures at least 32% of that of Jedicke (i.e. a secondary-to-primary mean-diameter ratio of ≥ 0.32), which translates into a diameter of 0.8–1.1 kilometers, depending on the underling size estimate of its primary. The "Johnstonsarchive" estimates that the moon has a semi-major axis of 4.4 kilometers.

He contributed to other scientific journals, and made an immense number of contributions to the Australian press. chromolithograph by Trouvelot In 1872 a equatorial refracting scope was purchased for the observatory, in 1881 Tebbutt discovered another great comet, now designated C/1881 K1, and in 1886 a new telescope of aperture and focal length was purchased, which enabled him to considerably extend his operations. He published in 1887 History and description of Mr. Tebbutt's observatory, Windsor, New South Wales, and followed this with a yearly Report for about 15 years. Between 1868 and 1902 he made 396 lunar occultation observations. A branch of the British Astronomical Association was established at Sydney in 1895 and Tebbutt was elected its first president.

Location of Soviet Venus landers On March 1, 1966 the Venera 3 Soviet space probe crash-landed on Venus, becoming the first spacecraft to reach the surface of another planet. Its sister craft Venera 2 had failed due to overheating shortly before completing its flyby mission. The descent capsule of Venera 4 entered the atmosphere of Venus on October 18, 1967, making it the first probe to return direct measurements from another planet's atmosphere. The capsule measured temperature, pressure, density and performed 11 automatic chemical experiments to analyze the atmosphere. It discovered that the atmosphere of Venus was 95% carbon dioxide (), and in combination with radio occultation data from the Mariner 5 probe, showed that surface pressures were far greater than expected (75 to 100 atmospheres).

Bahrain has an ancient and historic background which arise from the presence of Shiite scholars. Some of them are listed as following: Maitham Al Bahrani, Kamal al- Deen Maitham bin Ali bin Maitham al-Bahrani, commonly known as Sheikh Maitham Al Bahrani was a leading 13th Century Twelver Eastern Arabian theologian, author and philosopher. Al Bahrani wrote on Twelver doctrine, affirmed free will, the infallibility of prophets and imams, the appointed imamate of `Ali, and the occultation of the Twelfth Imam.Juan Cole, Sacred Space and Holy War, IB Tauris, 2007 p33 Yusuf al-Bahrani Yusuf ibn Ahmed al-Bahrani (1695–1772) (Arabic: يوسف البحراني) was a Bahraini theologian and a dominant person in the intellectual development of Twelver Shia Islam.

In 1852, Subh-i-Azal was involved in an uprising in Takur, Iran, which was planned to coincide with the assassination attempt on the life of the Shah. Following the attempt, he and other Babis chose to go into exile in Baghdad. In Baghdad he lived as the generally acknowledged head of the community, but he kept his whereabouts secret from most of the community, instead keeping in contact with the Babis through agents, termed "witnesses", in Iran and Iraq to routinize the charismatic authority of the movement, and echoing "the supposed appointment of agents by the twelfth Imam during the lesser occultation." One of the most important "witnesses of the Bayán" who represented Subh-i-Azal in Baghdad was Sayyid Muhammad Isfahani.

Transit of mercury chord across the sun In the field of astronomy the term chord typically refers to a line crossing an object which is formed during an occultation event. By taking accurate measurements of the start and end times of the event, in conjunction with the known location of the observer and the object's orbit, the length of the chord can be determined giving an indication of the size of the occulting object. By combining observations made from several different locations, multiple chords crossing the occulting object can be determined giving a more accurate shape and size model. This technique of using multiple observers during the same event has been used to derive more sophisticated shape models for asteroids, whose shape can be highly irregular.

Apart from syzygy, the term eclipse is also used when a spacecraft reaches a position where it can observe two celestial bodies so aligned. An eclipse is the result of either an occultation (completely hidden) or a transit (partially hidden). The term eclipse is most often used to describe either a solar eclipse, when the Moon's shadow crosses the Earth's surface, or a lunar eclipse, when the Moon moves into the Earth's shadow. However, it can also refer to such events beyond the Earth–Moon system: for example, a planet moving into the shadow cast by one of its moons, a moon passing into the shadow cast by its host planet, or a moon passing into the shadow of another moon.

Antares near the Sun on 30 NovemberRadial velocity variations were observed in the spectrum of Antares in the early 20th century and attempts were made to derive spectroscopic orbits. It became apparent that the small variations could not be due to orbital motion, and were actually caused by pulsation of the star's atmosphere. Even in 1928, it was calculated that the size of the star must vary by about 20%. Antares was first reported to have a companion star by Johann Tobias Bürg during an occultation on April 13, 1819, although this was not widely accepted and dismissed as a possible atmospheric effect. It was then observed by Scottish astronomer James William Grant FRSE while in India on 23 July 1844.

The shape model is consistent with slightly non-spherical components, having a size ratio of 0.95 (with an average radius of 42.9 km), and exhibiting equilibrium figures for homogeneous rotating bodies. A comparison with grazing occultation event lightcurves taken in 2003 suggests that the real shape of the components do not depart much from Roche equilibrium figures (by more than 10%). Observations from the VLT-UT4 telescope equipped with an adaptive optics system in 2007 and lightcurve data analysis suggest that one of the components appears to have a 68 km bowl- shaped impact crater that may be the result of a violent collision of proto- Antiope into two equisized bodies. The impactor is calculated to have been more than 17 km in diameter.

This mode displays the major solar system objects from the Sun to Pluto, and Jupiter's moons, orbits of all solar system moons, all 550,000+ minor planets all positioned with their correct scale, position and phase. The user can move forward and backward in time at various rates, or type in a time and date for which to view the positions of the planets, and can select viewing location. The program can show the solar system the way it would look from any location at any time between 1 AD and 4000 AD. Using this tool a user can watch an eclipse (e.g., 2017 total solar eclipse) occultation, or astronomical alignment, and preview where the best spot might be to observe a future event.

To this end he developed systems of interpretation of the Quran and sought to inform himself of all the sciences current in the Muslim world. He also evinced a veneration of the Imams, even beyond the extent of his pious contemporaries and espoused heterodox views on the afterlife, the resurrection and end-times, as well as medicine and cosmology. His views on the soul posited a "subtle body" separate from, and associated with the physical body, and this also altered his views on the occultation of the Imam Muhammad al-Mahdi. His views resulted in his denunciation by several learned clerics, and he engaged in many debates before moving on to Persia where he settled for a time in the province of Yazd.

Throughout history, various individuals have claimed to be or were proclaimed to be the Mahdi. These have included Muhammad Jaunpuri, founder of the Mahdavia sect; the Báb (Siyyid Ali Muhammad), founder of Bábism; Muhammad Ahmad, who established the Mahdist State in Sudan in the late 19th century; Mirza Ghulam Ahmad, founder of the Ahmadiyya movement; Massoud Rajavi, leader of the MEK, Riaz Ahmed Gohar Shahi, and Wallace Fard Muhammad, founder of the Nation of Islam. Shi'ites have alternate views on which descendant of the Islamic Nabi (Prophet) Muhammad is the Mahdi. Twelvers, who form the majority of Shi'ites today, believe that Muhammad al-Mahdi who is the son of the 11th Imam Al-Hasan al-Askari is in occultation and is the awaited Mahdi.

The Mahdi became synonymous with the "Hidden Imam" who was thought to be in occultation awaiting the time that God has ordered for his return. Muhammad said: “I swear by Him Who sent me with the truth as a bearer of glad tidings, the Qaim from my offspring will surely become concealed from public view on the basis of a covenant that has been entrusted to him from me,Muhammad Zakariya, al-Sahih wa al-Mu’tabar min Akhbar al-Hujjah al-Muntazar (Majmu’at al-Rasid; 1st edition, 1434 H), p. 14, # 1 This return is envisaged as occurring shortly before the final Day of judgment. In fact, the concept of the "hidden Imam" was attributed to several Imams in turn.

The spectrum continued to show complex and baffling features, with much of the energy from the central star being recycled into the infrared by surrounding dust, some reflection of light from the star from dense localised objects in the circumstellar material, but with obvious high ionisation features indicative of very high temperatures. The line profiles are complex and variable, indicating a number of absorption and emission features at various velocities relative to the central star. The 5.5 year orbital cycle produces strong spectral changes at periastron that are known as spectroscopic events. Certain wavelengths of radiation suffer eclipses, either due to actual occultation by one of the stars or due to passage within opaque portions of the complex stellar winds.

The call was suspended briefly between 19 May 1018 and 9 May 1019 CE during the apostasy of ad-Darazi and again between 1021 and 1026 CE during a period of persecution by Ali az-Zahir for those who had sworn the oath to accept the call. Persecutions started forty days after the disappearance into occultation of Al-Hakim, who was thought to have been converting people to a Unitarian faith for over twenty years prior. Al-Hakim convinced some heretical followers such as Ad-Darazi of his soteriological divinity and officially declared the Divine call after issuing a decree promoting religious freedom. The call summoned people to a true unitarian belief that removed all attributes (wise, just, outside, inside, etc.) from God.

Titania's surface is cut by a system of enormous canyons and scarps, the result of the expansion of its interior during the later stages of its evolution. Like all major moons of Uranus, Titania probably formed from an accretion disk which surrounded the planet just after its formation. Infrared spectroscopy conducted from 2001 to 2005 revealed the presence of water ice as well as frozen carbon dioxide on the surface of Titania, which in turn suggested that the moon may have a tenuous carbon dioxide atmosphere with a surface pressure of about 10 nanopascals (10−13 bar). Measurements during Titania's occultation of a star put an upper limit on the surface pressure of any possible atmosphere at 1–2 mPa (10–20 nbar).

In Shi’ism, the spiritual experience of kashf is treated as a theological rather than purely mystical dimension. :Imamis—Sayyid Haydar Amuli distinguishes three kinds of knowledge: 1) by the intellect, 2) by transmission, 3) by kashf—this is the only form of knowledge that leads to true understanding of Reality :Amuli additionally distinguishes between two kinds of kashf: :#kashf suwari—divine manifestations reach the senses of sight and hearing :# 'kashf ma’nawi—spiritual encounter, such as the disclosure indicated by mukashafa'' :Ismalis—these followers of Shi’ism put emphasis on kashf in a double sense as both a Gnostic and cosmic “state.” The Ismalis define “cycles of metahistory” which alternate between phases of “unveiling” (dawr-al-kashf) and “occultation” (dawr-al-satr).

In 1980, he established the Minor Planet Group and, in 1984, the Minor Planet Section (later the Asteroids and Remote Planets Section) of the BAA. In 1992, with R. Miles, he was awarded the Merlin Medal and Gift for the 1989 observations of the occultation of 28 Sagittarii by Titan. During the 1980s he was one of the first to use rapidly advancing technology in astronomical photometry, measuring the light from asteroids, satellites and stars using equipment he built with an RCA IP21 photomultiplier at its core. His measurements of asteroids were included in his doctoral dissertation: in 1992, he obtained one of the first PhDs available through the Open University with a thesis on the shapes of asteroids and their orbital evolution.

TWIM can provide global ionospheric electron density with timeThe TaiWan Ionospheric Model (TWIM) developed in 2008 is a three-dimensional numerical and phenomenological model of ionospheric electron density (Ne). The TWIM has been constructed from global distributed ionosonde foF2 and foE data and vertical Ne profiles retrieved from FormoSat3/COSMIC GPS radio occultation measurements. The TWIM consists of vertically fitted α-Chapman-type layers, with distinct F2, F1, E, and D layers, for which the layer parameters such as peak density, peak density height, and scale height are represented by surface spherical harmonics. These results are useful for providing reliable radio propagation predictions and in investigation of near-Earth space and large- scale Ne distribution with diurnal and seasonal variations, along with geographic features such as the equatorial anomaly.

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), the Infrared Astronomical Satellite IRAS, and the Japanese Akari satellite, Erda measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1942 and a diameter of 36.26 kilometers based on an absolute magnitude of 9.6. An alternative mean-diameter measurement published by the WISE team gives () with an albedo of (). On 17 April 2010, an asteroid occultation gave a best-fit ellipse dimension of 36.00 × 36.0 kilometers, while a second observation on 15 September 2014, measured an ellipse of 38.00 × 38.0 kilometers These timed observations are taken when the asteroid passes in front of a distant star.

However, at this point the Ismāʿīlī Imāms according to the Nizari and Mustaali found areas where they would be able to be safe from the recently founded Abbasid Caliphate, which had defeated and seized control from the Umayyads in 750 CE. At this point, some of the Ismaili community believed that Muhammad ibn Ismail had gone into the Occultation and that he would one day return. A small group traced the Imamat among Muhammad ibn Ismail's lineal descendants. With the status and location of the Imāms not known to the community, the concealed Ismaili Imams began to propagate the faith through Dāʿiyyūn from its base in Syria. This was the start of the spiritual beginnings of the Daʿwah that would later play important parts in the all Ismaili branches, especially the Nizaris and the Musta'lis.

299 The second split occurred following the death of al-Mustansir Billah in 1094 CE. His rule was the longest of any caliph in both the Fatimid and other Islamic empires. After he died, his sons Nizar, the older, and al- Musta'li, the younger, fought for political and spiritual control of the dynasty. Nizar was defeated and jailed, but according to Nizari sources his son escaped to Alamut, where the Iranian Ismāʿīlī had accepted his claim. The Mustaali line split again between the Taiyabi and the Hafizi, the former claiming that the 21st Imām and son of al-Amir bi-Ahkami'l-Lah went into occultation and appointed a Dāʿī al-Muṭlaq to guide the community, in a similar manner as the Ismāʿīlī had lived after the death of Muhammad ibn Ismail.

Before the rise of the Fatimid Caliphate, a small group of Ismailis, the Qarmatians, believed that Muhammad ibn Isma'il had gone into Occultation and were called "Seveners" to reflect their belief in only seven Imams, Muhammad's father Isma'il being the last until his return. The Qarmatians accepted a Persian prisoner by the name of Abu'l-Fadl al-Isfahani, who claimed to be the descendant of emperors, as the returned Muhammad ibn Isma'il and also as the Mahdi. The Qarmatians rampaged violently across the Middle East in the 10th century, climaxing their bloody campaign with the stealing of the Black Stone from the Kaaba in Mecca in 930 under Abu Tahir al- Jannabi. After the arrival of the Mahdi they changed their qibla from the Kaaba to the Zoroastrian-influenced fire.

Quadruple Saturn moon transit captured by Hubble Space Telescope Solar eclipses on Saturn occur when the natural satellites of Saturn pass in front of the Sun as seen from Saturn. For bodies which appear smaller in angular diameter than the Sun, the proper term would be a transit and which are larger than the apparent size of the Sun, the proper term would be an occultation. Seven of Saturn's satellites – Janus, Mimas, Enceladus, Tethys, Rhea, Dione and Titan – are large enough and near enough to eclipse or occult the Sun, or in other words to cast an umbra on Saturn. Most of the more distant satellites, besides being tiny, have orbits that are strongly inclined to the plane of Saturn's orbit, and would rarely be seen to transit.

Lawson observed an occultation of Saturn on 8 May 1832, Johann Gottfried Galle's first comet in December 1839 and January 1840, and recorded the falling stars of 12–13 November 1841. He published in 1844 a paper On the Arrangement of an Observatory for Practical Astronomy and Meteorology, and in 1847 a brief History of the New Planets. The Society of Arts, of which he was a member, voted Lawson a silver medal for the invention of an observing-chair called "Reclinea", and awarded him a prize for a new thermometer-stand, described before the British Association in 1845. He made communications to the British Association in 1846 and 1847 on solar telescopic work, and published in 1853 accounts of his designs for a "lifting apparatus" for invalids, and of a "surgical transferrer".

With a measured mean temperature of ~ , the upper limit of Quaoar's atmospheric pressure is expected to be in the range of a few microbars. Due to Quaoar's small size and mass, the possibility of Quaoar having an atmosphere of nitrogen and carbon monoxide has been ruled out, since the gases would escape from Quaoar. The possibility of a methane atmosphere, with the upper limit being less than 1 microbar, was considered until 2013, when Quaoar occulted a 15.8 magnitude star and revealed no sign of a substantial atmosphere, placing an upper limit to at least 20 nanobars, under the assumption that Quaoar's mean temperature is and that its atmosphere consists of mostly methane. The upper limit of atmosphere pressure was tightened to 10 nanobars after another stellar occultation in 2019.

He was the son of the fifth Dāʿī, Ali ibn Muhammad ibn al-Walid, and thus a member of the Banu al-Walid al-Anf family, that dominated the office of Dāʿī al-Muṭlaq almost continuously in the 13th to early 16th centuries. The position of Dāʿī al-Muṭlaq ("absolute/unrestricted missionary") was the supreme authority of the Tayyibi community in their capacity as vicegerents of the absent Imam, the eponymous at-Tayyib Abu'l-Qasim, who remained in occultation. Like his father, al-Husayn had close relations with the Rasulid dynasty of Sana'a, and converted several of their members to Tayyibi Isma'ilism, as well as the Banu Hatim branch of the Hamdanid dynasty of Dhu Marmar. Al-Husayn briefly moved the headquarters of the Tayyibi daʿwa to Dhu Marmar, before returning to Sana'a.

A-train satellite constellation as of 2014. An Earth observation satellite or Earth remote sensing satellite is a satellite used or designed for Earth observation (EO) from orbit, including spy satellites and similar ones intended for non-military uses such as environmental monitoring, meteorology, cartography and others. The most common type are Earth imaging satellites, that take satellite images, analogous to aerial photographs; some EO satellites may perform remote sensing without forming pictures, such as in GNSS radio occultation. The first occurrence of satellite remote sensing can be dated to the launch of the first artificial satellite, Sputnik 1, by the Soviet Union on October 4, 1957. Sputnik 1 sent back radio signals, which scientists used to study the ionosphere. NASA launched the first American satellite, Explorer 1, on January 31, 1958.

The recording of the lightcurve continues during and for a short time after the predicted event. This extra recording time is due in part to uncertainties in the occulting objects orbit but also due to the possibility of detecting other objects orbiting the primary object (for example in the case of a binary asteroid, also the ring system around the planet Uranus was detected this way). The exact method of lightcurve determination is dependent on the specific equipment available to the observer and the goals of the observation, however in all occultation events accurate timing is an essential component of the observation process. The exact time that the foreground object eclipses the other can be used to work out a very precise position along the occulting object's orbit.

According to Musta'lī tradition, after the death of al-Amir bi-Ahkami'l-Lah, his infant son, At- Tayyib Abu'l-Qasim, about two years old, was protected by Arwa al-Sulayhi who died in 1138, wife of the chief Fatimid Da'i of Yemen. She had been promoted to the post of Hujjat al-Islam long before by al-Mustansir Billah when her husband died and ran the Fatimid dawah from Yemen in the name of Imam At- Tayyib Abu'l-Qasim. During her leadership At-Tayyib Abu'l-Qasim went into occultation so she instituted the office of Da'i al-Mutlaq. Zoeb bin Moosa was first to be instituted to this office and the line of Taiyabi Da'is that began in 1132 has passed from one Da'i to another up to the present day.

Ring systems around minor bodies had not previously been discovered despite the search for them through direct imaging and stellar occultation techniques. Chariklo's rings should disperse over a period of at most a few million years, so either they are very young, or they are actively contained by shepherd moons with a mass comparable to that of the rings. However, other research suggests that Chariklo's elongated shape combined with its fast rotation can clear material in an equatorial disk through Lindblad resonances and explain the survival and location of the rings, a mechanism valid also for the ring of Haumea. The team nicknamed the rings Oiapoque (the inner, more substantial ring) and Chuí (the outer ring), after the two rivers that form the northern and southern coastal borders of Brazil.

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Bredichina measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0730 and a diameter of 91.60 kilometers based on an absolute magnitude of 8.65, while Carry give a diameter of and estimates a mass of kilogramm. Alternative mean-diameter measurements published by the WISE team include (), (), (), () and () with corresponding albedos of (), (), (), () and (). On 10 January 2015, an asteroid occultation of Bredichina gave a best-fit ellipse dimension of (), indicative of a highly elongated shape, with a good quality rating of 3.

The title al-Qāʾim Āl Muḥammad (, "the one who rises of the family of Muḥammad"), also al-Qāʾim bi ʾl-sayf ("the one who rises with the sword") or al-Qāʾim bi-amr Allāh ("the one who carries out the order of God"), is given to a messiah-like figure in the eschatology of Shia Islam, sometimes equated with the Mahdi. The term first came into use in the eighth century to refer to a future member of the family of Muḥammad who would rise up and defeat the wicked rulers of the age and restore justice. According to some Imāmī ḥadīths, every imām is the qāʾim of his age (al-qāʾim ahl zamānihi). The twelfth and last imām, who is in occultation and will return, is commonly known as Muḥammad al-Qāʾim.

The smallest KBO yet detected at that time was discovered in 2009 by poring over data from the Hubble Space Telescope's fine guidance sensors. They detected a transit of an object against a distant star, which, based on the duration and amount of dimming, was calculated to be a KBO about in diameter. It has been suggested that the Kepler observatory may be able to detect objects in the Oort cloud by their occultation of background stars,DETECTABILITY OF OORT CLOUD OBJECTS USING KEPLER - 2009 and the Whipple proposal would also try to use this concept A Hubble FGS has also been used for astrometry, tracking the movement of different starts. This ability was used for exoplanet research, where the motion of the star caused by the movement of planets around it was detected.

Launch of Mariner 5 Mariner 5 (Mariner Venus 1967) was a spacecraft of the Mariner program that carried a complement of experiments to probe Venus' atmosphere by radio occultation, measure the hydrogen Lyman-alpha (hard ultraviolet) spectrum, and sample the solar particles and magnetic field fluctuations above the planet. Its goals were to measure interplanetary and Venusian magnetic fields, charged particles, plasma, radio refractivity and UV emissions of the Venusian atmosphere. Mariner 5 was actually built as a backup to Mariner 4, but after the success of the Mariner 4 mission, it was modified for the Venus mission by removing the TV camera, reversing and reducing the four solar panels, and adding extra thermal insulation. Liftoff took place on June 14, 1967 from Cape Canaveral Air Force Station Launch Complex 12 on Atlas vehicle 5401.

A member of the Banu Hamdan tribe, Ali ibn Hanzala had been active within the Tayyibi daʿwa, already during the tenure of the third Dāʿī al- Muṭlaq, Hatim ibn Ibrahim (1162–1199). Under the fifth Dāʿī al-Muṭlaq, Ali ibn Muhammad ibn al-Walid (1209–1215), he served as his senior deputy (maʾdhūn) and succeeded him when the latter died in 1215. The position of Dāʿī al-Muṭlaq ("absolute/unrestricted missionary") was the supreme authority of the Tayyibi community in their capacity as vicegerents of the absent Imam, the eponymous at-Tayyib Abu'l-Qasim, who remained in occultation. Like most of his predecessors and successors, Ali enjoyed good relations with the Hamdanid dynasty ruling Sanaa and their Ayyubid overlords, which allowed him to reside both in Sanaa and in the Hatimid Hamdanid stronghold of Dhu Marmar.

None of the observers of this occurrence (including some using 'Super RADOTS' telescopes) reported seeing the ashen light. Video from the event was captured, but the camera was too insensitive to detect even the earthshine.2001 Jul 17 Reappearance of Venus from the Marshall Islands , by Peter Rejcek. See page 8. Retrieved 2015-10-25. A particularly favourable viewing opportunity occurred on 8 October 2015, with a 40% illuminated Venus reappearing from behind the unlit limb of a 15% sunlit Moon. The event was visible in dark skies throughout Central Australia and was recorded by David and Joan Dunham (of the International Occultation Timing Association) using a 10" f/4 Newton telescope with a Watec 120N+ video camera from a location just north of Alice Springs. They also observed the event visually with an 8" Schmidt–Cassegrain telescope.

Once the planetary nature of Kepler-5b was established, the Kepler team searched for the planet's occultation behind its star, hoping to find the temperature on its day side. They found both, and were able to set the equilibrium temperature of the planet. The use of speckle imaging using adaptive optics at the WIYN Observatory in Arizona and the Palomar Observatory in California isolated the starlight of Kepler-5 from background stars. Use of the Fibre-fed Echelle Spectrograph (FIES) at the Nordic Optical Telescope on the Canary Islands on June 4, 2009 provided data that was used to determine the star's stellar classification. The W.M. Keck Observatory's High Resolution Echelle Spectrometer (HIRES), which was used on June 3–6, 2009, and July 2–4, 2009, determined radial velocity measurements for the star, which helped to further define stellar parameters.

The Gospel of John 8:57 mentions in passing an upper limit of 50 for Jesus' age when preaching: "The Jews therefore said unto him, Thou art not yet fifty years old, and hast thou seen Abraham?" Fifty years is a round number which emphasises the discrepancy to Jesus's claim he had existed before Abraham, that is, for more than a thousand years.Colin Humphreys, The Mystery of the Last Supper Cambridge University Press 2011 , page 72 Some commentators have attempted to establish the date of birth by identifying the Star of Bethlehem with some known astronomical or astrological phenomenon. For example, astronomer Michael Molnar proposed 17 April 6 BC as the likely date of the Nativity, since that date corresponded to the heliacal rising and lunar occultation of Jupiter, while it was momentarily stationary in the constellation of Aries.

Traditional jurists, by employing ijtihad, have arrived at this judgment and have claimed consensus by relying on solitary (akhbar wahid) or dependable (muwatthaqah) hadiths. The ruling on killing the apostate and defamer of the Prophet is incorrect and not possible to implement on account of the following seven proofs: (a) The necessity of stopping the implementation of the rule of execution of an apostate or a blasphemer as a secondary injunction, “debilitating Islam” (avoiding the harm or seeking public welfare or governmental injunction). (b) The necessity of suspending or stopping the implemention of a punishment for hudud that would lead to killing of a person during the Occultation of the Twelfth Imam. (c) Since the judgment on killing is based on solitary reports (al-akhbar al-ahad), it is mandatory to exercise caution by negation of rule of shedding someone's blood.

He verified its observations about certain peculiarities in Ptolemy's theory of the Moon's motion, by conducting on 9 March 1497 at Bologna a memorable observation of the occultation of Aldebaran, the brightest star in the Taurus constellation, by the moon. Copernicus the humanist sought confirmation for his growing doubts through close reading of Greek and Latin authors (Pythagoras, Aristarchos of Samos, Cleomedes, Cicero, Pliny the Elder, Plutarch, Philolaus, Heraclides, Ecphantos, Plato), gathering, especially while at Padua, fragmentary historic information about ancient astronomical, cosmological and calendar systems. Copernicus spent the jubilee year 1500 in Rome, where he arrived with his brother Andrew that spring, doubtless to perform an apprenticeship at the Papal Curia. Here, too, however, he continued his astronomical work begun at Bologna, observing, for example, a lunar eclipse on the night of 5–6 November 1500.

South America is visible. The minimum angular separation would be less than 1′, and occasionally the Moon would be seen to transit in front of or pass behind (be occulted by) the Earth. The former case would correspond to a lunar occultation of Mars as seen from Earth, and because the Moon's albedo is considerably less than that of the Earth, a dip in overall brightness would occur, although this would be too small to be noticeable by casual naked eye observers because the size of the Moon is much smaller than that of the Earth and it would cover only a small fraction of the Earth's disk. Mars Global Surveyor imaged the Earth and Moon on May 8, 2003 13:00 UTC, very close to maximum angular elongation from the Sun and at a distance of 0.930 AU from Mars.

An artist's rendering of Chariklo with its rings The minor planet and centaur 10199 Chariklo, with a diameter of about , is the smallest celestial object with confirmed rings and the fifth ringed celestial object discovered in the Solar System, after the gas giants and ice giants. Orbiting Chariklo is a bright ring system consisting of two narrow and dense bands, 6–7 km (4 mi) and 2–4 km (2 mi) wide, separated by a gap of . The rings orbit at distances of about from the centre of Chariklo, a thousandth the distance between Earth and the Moon. The discovery was made by a team of astronomers using ten telescopes at various locations in Argentina, Brazil, and Chile in South America during observation of a stellar occultation on 3 June 2013, and was announced on 26 March 2014.

With regard to the problem of how the world comes by , Utpaladeva rejects the Advaita Vedānta theory of eternal and independent ignorance (avidyā),Abhinavagupta and His Works – V. Raghavan, p. 28 which affirms that brahman (the absolute consciousness) is being affected by avidyā (eternal ignorance) by superposition, with a resulting enslavement of the inactive, subject consciousness to worldly life. In Kashmir Shaivism, avidyā (ignorance) and its cosmic aspect, māyā (illusion), are nothing but Śakti, the power of Śiva; as Śakti, they are real for limited beings, but are simple manifestations of consciousness for Śiva. In Advaita Vedānta, with regard to the limited being (jiva), all activity belongs to the intellect (buddhi); in Kashmir Shaivism, activity is also ascribed to ātman, who is not inert, but in possession of the five-fold actions of creation, maintenance, dissolution, occultation, and grace.

The political asceticism practiced by the Imāms during the period after Muhammad ibn Ismail was to be short lived and finally concluded with the Imāmate of Abdullah al-Mahdi Billah, who was born in 873. After decades of Ismāʿīlīs believing that Muhammad ibn Ismail was in the Occultation and would return to bring an age of justice, al-Mahdi taught that the Imāms had not been literally secluded, but rather had remained hidden to protect themselves and had been organizing the Da'i, and even acted as Da'i themselves. After raising an army and successfully defeating the Aghlabids in North Africa and a number of other victories, al-Mahdi Billah successfully established a Shiʻi political state ruled by the Imāmate in 910. This was the only time in history where the Shiʻa Imamate and Caliphate were united after the first Imam, Ali ibn Abi Talib.

In the Bahá'í Faith, which sees the Báb as fulfilling the Islamic prophecy of al-Mahdi, Bahá'u'lláh and `Abdu'l-Bahá considered the story of the Occultation of the twelfth imam in Twelver belief to have been a pious fraud conceived by a number of the leading Shias in order to maintain the coherence and continuity of the Shia movement after the death of the 11th Imam, Hasan al-Askari.Momen, Moojan. Shi`i Islam and the Baha'i Faith Bahá'ís believe that Sayyid Ali Muhammad Shirazi, known as the Báb, is the promised Twelfth Imam, the Mahdi, who had already made his advent and fulfilled all the prophecies. The Báb was publicly executed on July 9, 1850 A.D. The Bab repeatedly talked about a messianic figure in his writings called He Whom God shall make manifest that would appear after him and would be the origin of all divine attributes.

This provided data for a coordinated study of the structure, chemistry, energy balance, and physical action of the Earth's middle atmosphere – that slice of air between 10 and 60 miles above the Earth. The UARS was the first major flight element of NASA's Mission to Planet Earth, a multi-year global research program that would use ground-based, airborne, and space-based instruments to study the Earth as a complete environmental system. UARS had ten sensing and measuring devices: Cryogenic Limb Array Etalon Spectrometer (CLAES); Improved Stratospheric and Mesospheric Sounder (ISAMS); Microwave Limb Sounder (MLS); Halogen Occultation Experiment (HALOE); High Resolution Doppler Imager (HRDI); Wind Imaging Interferometer (WlNDII); Solar Ultraviolet Spectral Irradiance Monitor (SUSIM); Solar/Stellar Irradiance Comparison Experiment (SOLSTICE); Particle Environment Monitor (PEM) and Active Cavity Radiometer Irradiance Monitor (ACRIM II). UARS's initial 18-month mission was extended several times – it was finally retired after 14 years of service.

This resulting shape appeared to be inconsistent with a homogenous body in hydrostatic equilibrium, though Haumea appears to be one of the largest trans-Neptunian objects discovered nonetheless, smaller than , , similar to , and possibly , and larger than , , and . A 2019 study attempted to resolve the conflicting measurements of Haumea's shape and density using numerical modeling of Haumea as a differentiated body. It found that dimensions of ≈ 2,100 × 1,680 × 1,074 km (modeling the long axis at intervals of 25 km) were a best-fit match to the observed shape of Haumea during the 2017 occultation, while also being consistent with both surface and core scalene ellipsoid shapes in hydrostatic equilibrium. The revised solution for Haumea's shape implies that it has a core of approximately 1,626 × 1,446 × 940 km, with a relatively high density of ≈ , indicative of a composition largely of hydrated silicates such as kaolinite.

Also, since the duration of the drop in the measured lightcurve gives the object's size and since occultation events typically only last somewhere on the order of a few seconds, very fast integration times are required to allow for high temporal resolution along the lightcurve. A second method of achieving very high temporal accuracy is to actually use a long exposure and allow the target star to drift across the CCD during the exposure. This method, known as the trailed image method, produces a streak along the photograph whose thickness corresponds to the brightness of the target star with the distance along the streak direction indicates time; this allows for very high temporal accuracy even when the target star may be too dim for the method described above using high frequency short exposures. With high enough temporal resolution even the angular size of the background star can be determined.

Kamal al-Deen Maitham bin Ali bin Maitham al-Bahrani (, 1238 – 1299), commonly known as Sheikh Maitham Al Bahrani (also spelt Maytham al-Bahrani) was a leading 13th Century Twelver Eastern Arabian theologian, author and philosopher. Al Bahrani wrote on Twelver doctrine, affirmed free will, the infallibility of prophets and imams, the appointed imamate of `Ali, and the occultation of the Twelfth Imam.Juan Cole, Sacred Space and Holy War, IB Tauris, 2007 p33 Along with Kamal al-Din Ibn Sa’adah al Bahrani, Jamal al-Din ‘Ali ibn Sulayman al-Bahrani, Maytham Al Bahrani was part of a 13th-century Bahrain school of theology that emphasised rationalism.Ali Al Oraibi, Rationalism in the school of Bahrain: a historical perspective, in Shīʻite Heritage: Essays on Classical and Modern Traditions By Lynda Clarke, Global Academic Publishing 2001 p331 At the same time, Maytham Al Bahrani was profoundly influenced by the disciplines of philosophy and mysticism.

Jupiter (the bright object in the upper right) a few minutes before being occulted by the Moon on June 16, 2005 An occultation is an astronomical event where a celestial object appears completely hidden by another, closer body (with a greater angular diameter) due to the passage of the closer object directly between the more distant object and the observer. Due to the large apparent size of the Moon, lunar occultations are quite common and when a bright celestial object is involved, the result is an event that can be easily observed using the naked eye. The Moon almost constantly occults faint stars as it orbits the Earth but because even a young Moon appears immensely brighter than these stars, these events are difficult to observe using amateur telescopes. However, the Moon does frequently occult brighter stars and even planets due to its close proximity to the ecliptic.

The deputies undertook the tasks of Imams to release them from the pressure of the Abbasids. Shia tradition holds that the Four Deputies acted in succession: # Uthman ibn Sa'id al-Asadi (873–874): He was the first deputy appointed by 12th Imam who governed for one year; # Abu Jafar Muhammad ibn Uthman (874–916): He was the second deputy appointed by 12th Imam for forty-two years; # Abu al-Qasim al-Husayn ibn Ruh al-Nawbakhti (916–937): He was the third deputy appointed by Al-Mahdi for twenty-one years; # Abu al-Hasan Ali ibn Muhammad al-Samarri (937–940): He was the last deputy of 12th Imam for three years. In 941 (329 AH), the fourth deputy announced information from Imam Hujjat-Allah al-Mahdi that the deputy would soon die and that the deputyship would end, beginning the Major Occultation. The fourth deputy died six days later, and Twelvers continue to await the reappearance of the Mahdi.

AE Phoenicis is a variable star in the constellation of Phoenix. An eclipsing binary, its apparent magnitude has a maximum of 7.56, dimming to 8.25 during primary eclipse and 8.19 during secondary eclipse. From parallax measurements by the Gaia spacecraft, the system is located at a distance of from Earth. AE Phoenicis is a contact binary of W Ursae Majoris type, composed of two stars so close that their surfaces touch each other. They are separated by 2.70 solar radii and orbit each other with a period of 0.3624 days. They are both classified as G-type main-sequence stars of spectral type G0V. With effective temperatures of 6,083 and 6,310 K, the system is classified as a W Ursae Majoris variable of subtype W, where the secondary star is hotter than the primary; for this reason, the primary eclipses are caused by the occultation of the secondary star. The orbit is circular and is inclined by 86.5° in relation to the plane of the sky.

The timing of the mission was important, as it would have passed Pluto shortly before its atmosphere froze, which it was thought to do for a considerable part of its orbit. The mission's main objectives would have been to map Pluto's surface and examine the double system's geology and geomorphology, as well as determining the composition of Pluto's atmosphere. This last task would have been considerably more difficult after the start of atmospheric freezing. Scientific equipment on board would have included visible light imaging systems, infrared and ultraviolet spectrometers, and an ultrastable oscillator (USO) for use in a radio occultation experiment. The spacecraft was to have been a simple hexagonal prism shaped structure weighing some 220 kg (485 lb), powered by radioisotope thermal generators (RTGs) similar to those used on the Galileo and Cassini missions. On-board control and data collection would have been maintained by a 1.5 MIPS RISC-based computer system capable of processing data at 5 Mbit/s.

Eclipses of the Sun from Jupiter are not particularly rare, since Jupiter is very large and its axial tilt (which is related to the plane of the orbits of its satellites) is relatively small—indeed, the vast majority of the orbits of all five of the objects capable of occulting the Sun will result in a solar occultation visible from somewhere on Jupiter. The related phenomenon of satellite eclipses in the shadow of Jupiter has been observed since the time of Giovanni Cassini and Ole Rømer in the mid Seventeenth Century. It was soon noticed that predicted times differed from observed times in a regular way, varying from up to ten minutes early to up to ten minutes late. Rømer used these errors to make the first accurate determination of the speed of light, correctly realizing that the variations were caused by the varying distance between Earth and Jupiter as the two planets moved in their orbits around the Sun.

V752 Centauri (HD 101799) is multiple star system and variable star in the constellation of Centaurus. An eclipsing binary, its apparent magnitude has a maximum of 9.10, dimming to 9.66 during primary eclipse and 9.61 during secondary eclipse. Its variability was discovered by Howard Bond in 1970. From parallax measurements by the Gaia spacecraft, the system is located at a distance of from Earth. V752 Centauri is a contact binary of the W Ursae Majoris type, composed of two F-type stars with a combined spectral type of F7/G0(V). Individually, the components have been classified as F8 \+ F5, and F8 \+ F7.5. With effective temperatures of 5,955 and 6,221 K, the system is classified as a W Ursae Majoris variable of subtype W, where the secondary star is hotter than the primary; for this reason, the primary eclipses are caused by the occultation of the secondary star. The system has an orbital period of only 0.3702 days and a separation of 2.59 solar radii.

The Shia millennial vision of history continues to be expressed, even today, through radical social protest against political oppression. Abdulaziz Sachedina writes: "Without the deep sense of paving the way for the reappearance of the Imam, the Shi'as would not have felt the need to re-evaluate their social circumstances and the shortcomings of their present lives. Thus, the ghayba (occultation) of the Mahdi has acted as a creative force in their lives that has not only helped them bear with patience the difficult times but also has also prepared them to fulfill their historical responsibility of establishing a true Islamic rule, even before the Imam assumes the leadership of the Shia after his final reappearance." The Shia Mahdi doctrine was a key element in inspiring the 1979 Islamic revolution in Iran led by Ayatollah Ruhollah Khomeini who argued as part of his theory of the Rule of the Jurist that the highest and most learned Muslim Jurist could legitimately administer the government on a God-given mandate to prepare the world for the return of the Hidden Imam.

In Karbala he became the prestigious dean of the Shi'i scholarship and as such presided over the religious establishment.Juan Cole, Sacred Space and Holy War, IB Tauris, 2007 p71 Al-Bahrani adopted the Akbhari school, rejecting his early Usuli schooling in Bahrain. Al-Bahrani's thought evolved from a strict Akhbarism to a position that adopted some Usuli elements; he became his generation's chief proponent of the neo-Akhbari creed.Juan Cole, Sacred Space and Holy War, IB Tauris, 2007 p53 Nevertheless, he rejected Usuli principles of legal reasoning, the syllogistic logic Usulis allowed in interpreting the law, and the legitimacy of holy war during the Occultation of the Imam.Roots of North Indian Shi‘ism in Iran and Iraq, Religion and State in Awadh, 1722-1859 Juan Cole, University of California Press, 1989 Historian Juan Cole summarises al-Bahrani's thought as:It has been proposed by that al-Bahrani may have found the state-centric Usulism less appealing given the political turmoil he had experienced throughout his life: first as a refugee from his homeland and then again when the Safavids were deposed by Afghan invaders.

It was during this time—approximately 1774—that he met Charles Messier, and apparently, they became friends. In the same year, he also produced his first astronomical work, a paper on an occultation of Aldebaran by the Moon and presented it as a memoir to the Academy of Sciences. In 1777, he married Barbe-Thérèse Marjou whom he knew from his work in Versailles. They had two sons: Jérôme, born 1780, and Augustin, born 1784, and one daughter. He was admitted to the French Académie des sciences in 1782, and was the editor of Connaissance des Temps from 1785 to 1792; this was the journal which, among other things, first published the list of Messier objects. In 1789 he was elected a Fellow of the Royal Society. He participated in the Anglo-French Survey (1784–1790) to measure by trigonometry the precise distance between the Paris Observatory and the Royal Greenwich Observatory. This project was initiated by Dominique, comte de Cassini, and in 1787 Méchain visited Dover and London with Cassini and Adrien-Marie Legendre to facilitate its progress.

Delta Cancri was involved in the first recorded occultation by Jupiter: Delta Cancri also marks the famous open star cluster Praesepe (or the Beehive Cluster, also known as Messier 44). In ancient times M44 was used as a weather gauge as the following Greek rhyme from Aratos' Prognostica reveals: The meaning of this verse is that if Asellus Borealis or Gamma CancrisKaler, 2009: is hidden by clouds, the wind will be from the south and that situation will be reversed if Asellus Australis is obscured. There is some doubt however as to the accuracy of this as Allen notes: "Our modern Weather Bureau would probably tell us that if one of these stars were thus concealed, the other also would be." (Allen, 1898) But Delta Cancri also acts as more than just a dubious weather guide: it is a reliable signpost for finding the vividly red star X Cancri as Patrick Moore notes in his guidebook Stars of the Southern Skies: Delta Cancri also marks the radiant of the Delta Cancrids meteor shower.

BEYOND THE BATTLE, THE QUIET STRUGGLE FOR IRAQ'S FUTURE , Financial Times Magazine, 2004-08-15, accessed on 2010-06-17 However, this report is contradicted by the official website of the Shi'a Marja, wherein he remarks, "The correct opinion regarding the issue of "Vilayat-e-Faqih" (Guardianship of the Islamic Jurist) is that this issue requires no external proof, because the continuation of Islamic law, and its application, is dependent upon the continuation of the system of Vilayat". He continues, "The vilayat of the Prophet and the immaculate Imams, and in the time of the major occultation of the 12th Imam, the Islamic Jurist is bestowed with this vilayat ... It is unimaginable that Islamic Law could continue to exist without the continuation of this vilayat".THE OFFICIAL WEBSITE OF SHEIKH ISHAQ AL-FAYYAD, IN ANSWER TO QUESTIONS REGARDING THE ISSUE OF "THE GUARDIANSHIP OF THE JURIST" Furthermore, he is one of the Ulama signatories of the Amman Message, which gives a broad foundation for defining Muslim orthodoxy.Al-Fayyad's official reply to Amman Message He has written a number of books on Islamic jurisprudence, Islamic politics, and Islamic banking.

148/765), as opposed to "Twelvers" who believe that Musa al-Kadhim (d. 183/799) was designated imam over his younger brother Ismāʿīl. After the Abbasid Revolution of 750 CE Ismāʿīlīs came to believe that Muhammad ibn Ismail, son of the seventh imam and their awaited mahdi, had entered a state of occultation. In his absence Isma'ilis began widely propagating their faith beyond their base of power in Salamiyah through the institution of the da‘wa, or mission led by a dā‘ī. In addition to presiding over the primary missionary activities of the da‘wa, the dā‘ī was responsible for the education, safety and spiritual health of his community. The personal relationship of the dā‘ī and his students, portrayed so vividly by Ja'far ibn Mansur al-Yaman in his work, would decisively influence the sheikh-murīd bond of later Sufi orders. With the rise of the Fatimid Caliphate in the first quarter of the tenth century CE, the Isma'ilis identified these caliphs with their imams. In this manner the Kitāb is to be viewed as a classic of early Fatimid literature, documenting important aspects of the development of the Isma'ili da‘wa in tenth-century Yemen.

In 2004 Jonathan Beckett released the song 'She's a Vampire', written in 1998, it was released as part of a home-produced five-track EP. Beckett's music attracted the attention of Paul Simpson of The Wild Swans who stated: > "I'm a sucker for musical beauty, lyrical sadness and outsiderism, and they > don't come more beautifully outsider than Jonathan Beckett. For me, > stumbling upon Jonathan's music is a bit like chancing upon the ivy-covered > remains of an architecturally significant stately home while out walking in > the woods; a little decayed, ever so slightly scary perhaps, but beneath the > ivy lie elegant mullioned windows, intricately carved stone bestiary and > secret doors in the oak paneling." Later, In June 2010, Beckett released an E.P. which shared the name of the song 'She's a Vampire'; this also featured the song 'Between Two Worlds', which was originally released in 2003 on a home-produced album named Start Point. She's a Vampire was released on the same record label that The Wild Swans were on: Occultation Recordings, as Simpson put Beckett in contact with Nick Halliwell - the owner, the E.P. was later re-released on Echolocation Records as a download.

The European X-ray Observatory Satellite (EXOSAT), originally named HELOS, was an X-ray telescope operational from May 1983 until April 1986 and in that time made 1780 observations in the X-ray band of most classes of astronomical object including active galactic nuclei, stellar coronae, cataclysmic variables, white dwarfs, X-ray binaries, clusters of galaxies, and supernova remnants. This European Space Agency (ESA) satellite for direct-pointing and lunar-occultation observation of X-ray sources beyond the solar system was launched into a highly eccentric orbit (apogee 200,000 km, perigee 500 km) almost perpendicular to that of the moon on 26 May 1983. The instrumentation includes two low-energy imaging telescopes (LEIT) with Wolter I X-ray optics (for the 0.04–2 keV energy range), a medium-energy experiment using Ar/CO2 and Xe/CO2 detectors (for 1.5–50 keV), a Xe/He gas scintillation spectrometer (GSPC) (covering 2–80 keV), and a reprogrammable onboard data-processing computer. Exosat was capable of observing an object (in the direct-pointing mode) for up to 80 hours and of locating sources to within at least 10 arcsec with the LEIT and about 2 arcsec with GSPC.

A poster designed for the Magellan end of mission On September 9, 1994, a press release outlined the termination of the Magellan mission. Due to the degradation of the power output from the solar arrays and onboard components, and having completed all objectives successfully, the mission was to end in mid-October. The termination sequence began in late August 1994, with a series of orbital trim maneuvers which lowered the spacecraft into the outermost layers of the Venusian atmosphere to allow the Windmill experiment to begin on September 6, 1994. The experiment lasted for two weeks and was followed by subsequent orbital trim maneuvers, further lowering the altitude of the spacecraft for the final termination phase. On October 11, 1994, moving at a velocity of 7 kilometers/second, the final orbital trim maneuver was performed, placing the spacecraft 139.7 kilometers above the surface, well within the atmosphere. At this altitude the spacecraft encountered sufficient ram pressure to raise temperatures on the solar arrays to 126 degrees Celsius. On October 13, 1994 at 10:05:00 UTC, communication was lost when the spacecraft entered radio occultation behind Venus. The team continued to listen for another signal from the spacecraft until 18:00:00 UTC, when the mission was determined to have concluded.

The air circulated from the dayside also carries oxygen atoms, which after recombination form excited molecules of oxygen in the long-lived singlet state (1Δg), which then relax and emit infrared radiation at the wavelength 1.27 μm. This radiation from the altitude range 90–100 km is often observed from the ground and spacecraft. The nightside upper mesosphere and thermosphere of Venus is also the source of non-local thermodynamic equilibrium emissions of CO2 and nitric oxide molecules, which are responsible for the low temperature of the nightside thermosphere. The Venus Express probe has shown through stellar occultation that the atmospheric haze extends much further up on the night side than the day side. On the day side the cloud deck has a thickness of 20 km and extends up to about 65 km, whereas on the night side the cloud deck in the form of a thick haze reaches up to 90 km in altitude—well into mesosphere, continuing even further to 105 km as a more transparent haze. In 2011, the spacecraft discovered that Venus has a thin ozone layer at an altitude of 100 km. Venus has an extended ionosphere located at altitudes 120–300 km. The ionosphere almost coincides with the thermosphere.

During 1953–65 Prof. Swarup made the discovery of 'Type U' solar radio bursts; developed a gyro-radiation model for explaining the microwave solar emission and made studies of the radio emission from the Quiet Sun. In 1959 he developed a round trip transmission technique for phase measurements, which has been used in almost all the radio interferometers in the world. In 1962 he found the first example of a steep spectrum 'bridge' of radio emission between the two radio lobes of the powerful radio galaxy, Cyg-A, using the Stanford Compound Interferometer; such bridges allow estimates of the age of a radio galaxy. During 1963–70, he constructed a 530 m long and 30 m wide parabolic- cylindrical radio telescope of a unique and innovative design at Ooty in South India, which was placed on a suitably inclined hill so as to make its long axis of rotation parallel to that of the earth, enabling it to track celestial radio sources in hour angle for 9.5 hrs. Using the method of lunar occultation, it provided for the first time high-resolution angular data (1 to 10 arc sec) for more than 1,000 weak radio sources, which provided an independent evidence for the Big Bang model.