Editing Hipparchus (section)

{{Short description|2nd-century BC Greek astronomer, geographer and mathematician}}
{{about|the Greek astronomer|other uses|}}
{{Use dmy dates|date=September 2019}}
{{Infobox person
| name        = Hipparchus
| image       = Head of Hipparchus (cropped).jpg
| caption     = 19th century engraving based on an [[engraved gem|engraved]] [[amethyst]] from the [[Poniatowski gems|Poniatowski gem]] collection{{efn|name=head-of-hipparchus}}
| birth_date  = {{c.|lk=no|190}}&nbsp;BC
| birth_place = [[Nicaea]], [[Kingdom of Bithynia]]<br />(modern-day [[İznik, Bursa]], Turkey)
| death_date  = {{c.|lk=no|120}}&nbsp;BC (around age 70)
| death_place = [[Rhodes]], [[Roman Republic]]<br />(modern-day Greece)
| education   = 
| occupation  = {{hlist |[[Astronomer]] |[[Mathematician]] |[[Geographer]]}}
}}

'''Hipparchus''' ({{IPAc-en|h|ɪ|ˈ|p|ɑr|k|ə|s}}; {{langx|grc|[[wikt:Ἵππαρχος|Ἵππαρχος]]|label=[[Ancient Greek|Greek]]}}, {{#invoke:Ancient Greek|translit|Ἵππαρχος}}; {{c. |lk=no|190|120}}&nbsp;BC) was a [[Ancient Greek astronomy|Greek astronomer]], [[geographer]], and [[mathematician]]. He is considered the founder of [[trigonometry]],{{r|linton2004}} but is most famous for his incidental discovery of the [[precession of the equinoxes]].{{r|toomer1996}} Hipparchus was born in [[Nicaea]], [[Bithynia]], and probably died on the island of [[Rhodes]], Greece. He is known to have been a working astronomer between 162 and 127&nbsp;BC.{{r|mccluskey2000}}

Hipparchus is considered the greatest ancient astronomical observer and, by some, the greatest overall astronomer of [[classical antiquity|antiquity]].{{r|willard1854}}<ref>Denison Olmsted, Outlines of a Course of Lectures on Meteorology and Astronomy, pp 22</ref> He was the first whose quantitative and accurate models for the motion of the [[Sun]] and [[Moon]] survive. For this he certainly made use of the observations and perhaps the mathematical techniques accumulated over centuries by the [[Babylonia]]ns and by [[Meton of Athens]] (fifth century BC), [[Timocharis]], [[Aristyllus]], [[Aristarchus of Samos]], and [[Eratosthenes]], among others.{{r|jones2017}}

He developed trigonometry and constructed [[trigonometric tables]], and he solved several problems of [[spherical trigonometry]]. With his solar and [[lunar theory|lunar]] theories and his trigonometry, he may have been the first to develop a reliable method to predict [[solar eclipse]]s.{{citation needed|date=September 2024}}{{dubious|date=September 2024}}

His other reputed achievements include the discovery and measurement of Earth's precession, the compilation of the first known comprehensive [[star catalog]] from the western world, and possibly the invention of the [[astrolabe]], as well as of the [[armillary sphere]] that he may have used in creating the star catalogue. Hipparchus is sometimes called the "father of astronomy",{{r|newcomb1878}}{{r|glashan1895}} a title conferred on him by [[Jean Baptiste Joseph Delambre]] in 1817.{{r|delambre1817}}