The intellectual legacy of the brilliant astronomer Al-Sufi

by Guest Mon Oct 23, 2017 11:59 pm

ALL astronomers know the names of Ptolemy, Tycho Brahe, and Johannes Hevelius, three landmark characters who catalogued the stars with ever-increasing accuracy between the second and seventeenth centuries. Less familiar in the West, but no less influential, is the tenth-century Persian astronomer Ἁbd al-Raḥmān al-Ṣūfī (903–986), usually known simply as al-Ṣūfī, or Azophi in Latinized form. Al-Ṣūfī was the Arabic successor to Ptolemy at a time when the Greek tradition in astronomy had died out in the West but was being rediscovered in the Middle East.

Al-Ṣūfī, who ran an observatory in the Persian city of Shīrāz (now in Iran), used the star catalogue in Ptolemy’s Almagest as the basis for his own Arabic version called Kitāb al-Kawākib al-Thābitah, i.e. Book of the Fixed Stars. This appeared in or shortly after AD 964, some eight hundred years after the original Almagest was written. Al-Ṣūfī’s book, the first-ever updating of the Almagest, became the standard constellation handbook for several centuries thereafter, inspiring the development of Arabic astronomy and eventually aiding the transmission of Greek astronomy back into the West. Al-Ṣūfī was one of the four ancient authorities credited on the first European printed star chartsproduced by Albrecht Dürer in 1515.

Like all books in the days before printing, the Book of the Fixed Stars was written and illustrated by hand. Further copies had to be hand-made too, and each copy was unique and prone to loss or damage. Al-Ṣūfī’s original manuscript has disappeared, but we still have an early copy reputedly made by his son Ibn al-Ṣūfī and thought to date from 24 years after his father’s death, although some scholars consider it a much later copy by a different author. One of the treasures of astronomical history, this manuscript is kept in the Bodleian Library, Oxford, where it is catalogued as Marsh 144; it can be seen online here. Ibn al-Ṣūfī also based a poem about the stars on the book, thereby helping to popularize his father’s work. The first English translation of the Book of the Fixed Stars was published in 2013 by Ihsan Hafez of James Cook University, Australia.

Al-Ṣūfī’s book retained the same 48 constellations and their component stars as in the Almagest, but in the accompanying text he added information about traditional Bedouin Arabic constellations and Arabic star names. Most of the book consists of discussions of the constellations and their stars in Greek and Arabic tradition.

To the casual viewer, the main attraction of the book is the constellation illustrations, something that the original Almagest notably lacked. Each constellation was depicted twice, first in mirror image, as it would appear on a celestial globe, and secondly as it actually appears in the sky...

Al-Sufi’s book contains the first known record of three nebulous objects not mentioned by Ptolemy: the Andromeda Galaxy; Brocchi’s Cluster (the Coathanger); and the Omicron Velorum Cluster (IC 2391). These objects are mentioned only in al-Sufi’s text, and are not in the star tables, although the Andromeda Galaxy is shown in one of the accompanying illustrations...

We can never know how many copies of the Book of the Fixed Stars were made over the years, but over 90 are currently preserved in museums and libraries around the world. Each has its own individual features, because each copyist introduced their own version of the constellation figures, influenced by local style and tradition.

One of the most celebrated copies is one that was made in the 1430s and originally belonged to the great Muslim astronomer Ulugh Beg (1394–1449). This is now kept at the Bibliothèque Nationale de France and is known as MS Arabe 5036. Working at his own observatory in Samarkand, in modern Uzbekistan, Ulugh Beg reobserved the stars of the Almagest to produce the Zīj-i jadīd-i Sultānī, published in 1437, the most accurate star catalogue prior to that of Tycho Brahe, although it lacked the popular appeal of al-Ṣūfī’s illustrated version.

http://www.ianridpath.com/startales/alsufi.htm

by Guest Tue Oct 24, 2017 12:03 am

Messier 31 (M31), better known as the Andromeda Galaxy, is a large spiral galaxy located in the constellation Andromeda.
At a distance of 2.54 million light years from Earth, the Andromeda Galaxy is the nearest major galaxy to our own and is on a collision course with our home galaxy, the Milky Way...

The earliest record of M31 comes from the Persian astronomer Abd al-Rahman al-Sufi, who mentioned the chained constellation, referring to Andromeda, or the Chained Maiden, in his Book of Fixed Stars in 964. Al-Sufi described the Andromeda Galaxy as a “small cloud.”

http://www.messier-objects.com/messier-31-andromeda-galaxy/

by Guest Tue Oct 24, 2017 12:07 am

Abd al-Rahman Al-Sufi forever changed the way we look at the stars in the sky. As one of the world’s most influential astronomers, he dedicated his life to furthering our understanding of the stars and constellations. The lunar crater "Azophi" and the minor planet "12621 Alsufi" are named after him.

One of Al-Sufi's greatest works involved fact-checking the Greek astronomer Ptolemy's measurements of the brightness and size of stars. In the year 964 AD, Al-Sufi published his findings in a book titled Kitab al-Kawatib al-Thabit al-Musawwar, or The Book of Fixed Stars. In many cases, he confirmed Ptolemy’s discoveries, but he also improved upon his work by illustrating the constellations and correcting some of Ptolemy’s observations about the brightness of stars.

Today's Doodle celebrates Al-Sufi on what would be his 1,113th birthday with a representation of the constellation Cancer, also known as “the crab.” The artwork closely mirrors what appeared in Al-Sufi’s manuscript, The Book of Fixed Stars.The words around the crabs indicate the cardinal directions of North, South, East, and West, with the smaller labels providing additional assistance in viewing the constellations.

More than a millennium later, Al-Sufi's keen observations and detailed work still informs our view of the night sky.

http://www.google.com/doodles/abd-al-rahman-al-sufis-azophi-1113th-birthday

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The intellectual legacy of the brilliant astronomer Al-Sufi

The intellectual legacy of the brilliant astronomer Al-Sufi

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Re: The intellectual legacy of the brilliant astronomer Al-Sufi