Abd Al-Rahman Al Sufi
Encyclopedia
'Abd al-Rahman al-Sufi (December 7, 903 – May 25, 986) was a Persian
astronomer
also known as 'Abd ar-Rahman as-Sufi, or 'Abd al-Rahman Abu al-Husayn, 'Abdul Rahman Sufi, 'Abdurrahman Sufi and known in the west as Azophi; the lunar crater Azophi
and the minor planet
12621 Alsufi
are named after him. Al-Sufi published his famous Book of Fixed Stars
in 964, describing much of his work, both in textual descriptions and pictures.
, Persia
, and worked on translating and expanding Greek
astronomical works, especially the Almagest
of Ptolemy
. He contributed several corrections to Ptolemy's star
list and did his own brightness
and magnitude
estimates which frequently deviated from those in Ptolemy's work.
He was a major translator into Arabic of the Hellenistic astronomy that had been centred in Alexandria
, the first to attempt to relate the Greek
with the traditional Arabic
star names and constellation
s, which were completely unrelated and overlapped in complicated ways.
He identified the Large Magellanic Cloud
, which is visible from Yemen
, though not from Isfahan; it was not seen by Europeans until Magellan
's voyage in the 16th century. He also made the earliest recorded observation of the Andromeda Galaxy
in 964 AD; describing it as a "small cloud". These were the first galaxies
other than the Milky Way
to be observed from Earth.
He observed that the ecliptic
plane is inclined with respect to the celestial equator
and more accurately calculated the length of the tropical year
. He observed and described the stars, their positions, their magnitude
s and their colour, setting out his results constellation by constellation. For each constellation, he provided two drawings, one from the outside of a celestial globe, and the other from the inside (as seen from the earth).
Al-Sufi also wrote about the astrolabe
, finding numerous additional uses for it : he described over 1000 different uses, in areas as diverse as astronomy
, astrology, horoscopes, navigation
, surveying
, time
keeping, Qibla
, Salah prayer, etc.
in the memory of Sufi. The first competition was held in 2006 in the north of Semnan Province and the 2nd moe observing competition was held in summer of 2008 in Ladiz near the Zahedan.
More than 100 observers from Iran and Iraq participated in this event.
Persian people
The Persian people are part of the Iranian peoples who speak the modern Persian language and closely akin Iranian dialects and languages. The origin of the ethnic Iranian/Persian peoples are traced to the Ancient Iranian peoples, who were part of the ancient Indo-Iranians and themselves part of...
astronomer
Islamic astronomy
Islamic astronomy or Arabic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age , and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and...
also known as 'Abd ar-Rahman as-Sufi, or 'Abd al-Rahman Abu al-Husayn, 'Abdul Rahman Sufi, 'Abdurrahman Sufi and known in the west as Azophi; the lunar crater Azophi
Azophi (crater)
Azophi is a lunar impact crater that lies in the rugged south-central highlands of the Moon. The northwest rim is attached to the slightly smaller crater Abenezra. To the east-southeast is the large and irregular Sacrobosco....
and the minor planet
Minor planet
An asteroid group or minor-planet group is a population of minor planets that have a share broadly similar orbits. Members are generally unrelated to each other, unlike in an asteroid family, which often results from the break-up of a single asteroid...
12621 Alsufi
12621 Alsufi
12621 Alsufi is a main belt asteroid with an orbital period of c. 2000 days . The asteroid was discovered on September 24, 1960.-References:...
are named after him. Al-Sufi published his famous Book of Fixed Stars
Book of Fixed Stars
The Book of Fixed Stars is an astronomical text written by Abd al-Rahman al-Sufi around 964. The book was written in Arabic, although the author himself was Persian...
in 964, describing much of his work, both in textual descriptions and pictures.
Biography
He was one of the famous nine Muslim astronomers His name implies that he was a Sufi Muslim. He lived at the court of Emir Adud ad-Daula in IsfahanIsfahan (city)
Isfahan , historically also rendered in English as Ispahan, Sepahan or Hispahan, is the capital of Isfahan Province in Iran, located about 340 km south of Tehran. It has a population of 1,583,609, Iran's third largest city after Tehran and Mashhad...
, Persia
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
, and worked on translating and expanding Greek
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
astronomical works, especially the Almagest
Almagest
The Almagest is a 2nd-century mathematical and astronomical treatise on the apparent motions of the stars and planetary paths. Written in Greek by Claudius Ptolemy, a Roman era scholar of Egypt,...
of Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
. He contributed several corrections to Ptolemy's star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
list and did his own brightness
Brightness
Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target...
and magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
estimates which frequently deviated from those in Ptolemy's work.
He was a major translator into Arabic of the Hellenistic astronomy that had been centred in Alexandria
Alexandria
Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...
, the first to attempt to relate the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
with the traditional Arabic
Arabic language
Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...
star names and constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
s, which were completely unrelated and overlapped in complicated ways.
Astronomy
Large Magellanic Cloud
The Large Magellanic Cloud is a nearby irregular galaxy, and is a satellite of the Milky Way. At a distance of slightly less than 50 kiloparsecs , the LMC is the third closest galaxy to the Milky Way, with the Sagittarius Dwarf Spheroidal and Canis Major Dwarf Galaxy lying closer to the center...
, which is visible from Yemen
Yemen
The Republic of Yemen , commonly known as Yemen , is a country located in the Middle East, occupying the southwestern to southern end of the Arabian Peninsula. It is bordered by Saudi Arabia to the north, the Red Sea to the west, and Oman to the east....
, though not from Isfahan; it was not seen by Europeans until Magellan
Ferdinand Magellan
Ferdinand Magellan was a Portuguese explorer. He was born in Sabrosa, in northern Portugal, and served King Charles I of Spain in search of a westward route to the "Spice Islands" ....
's voyage in the 16th century. He also made the earliest recorded observation of the Andromeda Galaxy
Andromeda Galaxy
The Andromeda Galaxy is a spiral galaxy approximately 2.5 million light-years from Earth in the constellation Andromeda. It is also known as Messier 31, M31, or NGC 224, and is often referred to as the Great Andromeda Nebula in older texts. Andromeda is the nearest spiral galaxy to the...
in 964 AD; describing it as a "small cloud". These were the first galaxies
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
other than the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
to be observed from Earth.
He observed that the ecliptic
Ecliptic
The ecliptic is the plane of the earth's orbit around the sun. In more accurate terms, it is the intersection of the celestial sphere with the ecliptic plane, which is the geometric plane containing the mean orbit of the Earth around the Sun...
plane is inclined with respect to the celestial equator
Celestial equator
The celestial equator is a great circle on the imaginary celestial sphere, in the same plane as the Earth's equator. In other words, it is a projection of the terrestrial equator out into space...
and more accurately calculated the length of the tropical year
Tropical year
A tropical year , for general purposes, is the length of time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox, or from summer solstice to summer solstice...
. He observed and described the stars, their positions, their magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
s and their colour, setting out his results constellation by constellation. For each constellation, he provided two drawings, one from the outside of a celestial globe, and the other from the inside (as seen from the earth).
Al-Sufi also wrote about the astrolabe
Astrolabe
An astrolabe is an elaborate inclinometer, historically used by astronomers, navigators, and astrologers. Its many uses include locating and predicting the positions of the Sun, Moon, planets, and stars, determining local time given local latitude and longitude, surveying, triangulation, and to...
, finding numerous additional uses for it : he described over 1000 different uses, in areas as diverse as astronomy
Islamic astronomy
Islamic astronomy or Arabic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age , and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and...
, astrology, horoscopes, navigation
Mariner's astrolabe
The mariner's astrolabe, also called sea astrolabe, was an inclinometer used to determine the latitude of a ship at sea by measuring the sun's noon altitude or the meridian altitude of a star of known declination. Not an astrolabe proper, the mariner's astrolabe was rather a graduated circle with...
, surveying
Surveying
See Also: Public Land Survey SystemSurveying or land surveying is the technique, profession, and science of accurately determining the terrestrial or three-dimensional position of points and the distances and angles between them...
, time
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
keeping, Qibla
Qibla
The Qiblah , also transliterated as Qibla, Kiblah or Kibla, is the direction that should be faced when a Muslim prays during salah...
, Salah prayer, etc.
Sufi Observing Competition
Since 2006, Astronomy Society of Iran – Amateur Committee (ASIAC) hold an international Sufi Observing CompetitionSufi Observing Competition
Sufi Observing Competition is an international competition and like Messier marathon, but more difficult with various subjects.Since 2006, Astronomical Society of Iran – Amateur Committee hold an international observing competition in the memory of Azophi...
in the memory of Sufi. The first competition was held in 2006 in the north of Semnan Province and the 2nd moe observing competition was held in summer of 2008 in Ladiz near the Zahedan.
More than 100 observers from Iran and Iraq participated in this event.
See also
- List of Muslim scientists
- List of Iranian scientists
- Astronomy in Islam
- Sufi Observing CompetitionSufi Observing CompetitionSufi Observing Competition is an international competition and like Messier marathon, but more difficult with various subjects.Since 2006, Astronomical Society of Iran – Amateur Committee hold an international observing competition in the memory of Azophi...