Ibn al-Samh

{{short description|Arab mathematician and astronomer}}

Abū al‐Qāsim Aṣbagh ibn Muḥammad ibn al‐Samḥ al‐Gharnāṭī al-Mahri{{cite book|last1=al-Andalusi|first1=Sa'id|title=Science in the Medieval World|date=2010|publisher=University of Texas Press|isbn=9780292792319|url=https://books.google.com/books?id=mcN7AAAAQBAJ&pg=PA64|language=en}} ({{Langx|ar|أصبغ المهري}}) (born 979, Córdoba; died 1035, Granada), also known as Ibn al‐Samḥ, was an Arab{{cite book|last1=Taton|first1=René|title=A General History of the Sciences|date=1966|publisher=Thames and Hudson|url=https://books.google.com/books?id=8bfaAAAAMAAJ&q=Ibn+al-Samh+|language=en}} mathematician and astronomer from Al-Andalus. He worked at the school founded by Al-Majriti in Córdoba, until political unrest forced him to move to Granada, where he was employed by Ḥabbūs ibn Māksan. He is known for treatises on the construction and use of the astrolabe, as well as the first known work on the planetary equatorium. Furthermore, in mathematics he is remembered for a commentary on Euclid and for contributions to early algebra, among other works.{{cite encyclopedia | editor = Thomas Hockey| last = Rius | first = Mònica | title=Ibn al‐Samḥ: Abū al‐Qāsim Aṣbagh ibn Muḥammad ibn al‐Samḥ al‐Gharnāṭī | encyclopedia = The Biographical Encyclopedia of Astronomers | publisher = Springer | date = 2007 | location = New York | pages = 568 | url=http://islamsci.mcgill.ca/RASI/BEA/Ibn_al-Samh_BEA.htm | isbn=978-0-387-31022-0|display-editors=etal}}{{Cite book|url=https://books.google.com/books?id=ndwsE1eJy3wC|title=Founding Figures and Commentators in Arabic Mathematics: A History of Arabic Sciences and Mathematics|last=Rashed|first=Roshdi|date=2013-03-07|publisher=Routledge|isbn=9781136620003|language=en}} He is one of several writers referred to in Latin texts as "Abulcasim."{{Cite book|url=https://books.google.com/books?id=qq8Luhs7rTUC&pg=PA216|title=Cosmos: An Illustrated History of Astronomy and Cosmology|last=North|first=John|date=2008-07-15|publisher=University of Chicago Press|isbn=9780226594415|pages=216|language=en}}

The exoplanet Samh, also known as Upsilon Andromedae c, is named in his honor as part of the IAU's NameExoWorlds project.{{Cite web|url=http://nameexoworlds.iau.org/names|title=NameExoWorlds|website=nameexoworlds.iau.org|access-date=2017-06-12|archive-date=2018-02-01|archive-url=https://web.archive.org/web/20180201043609/http://nameexoworlds.iau.org/names|url-status=dead}}