Al-Battani

Al-Battani, also known as Albatenius, was an Arab astronomer and mathematician who lived from around 858 to 929 CE. He spent most of his life observing the stars in Raqqa, located in modern-day Syria.

He significantly refined the measurement of the solar year, calculating its length to be exactly 365 days, 5 hours, 46 minutes, and 24 seconds. His calculation was incredibly accurate, differing from modern figures by mere minutes.

Al-Battani's astronomical works were translated into Latin during the 12th century, heavily influencing European astronomers like Copernicus and Tycho Brahe. His precise data allowed later scientists to verify and refine their own astronomical models.

Yes, he made significant advancements in trigonometry, introducing the use of sines and cosines to Islamic mathematics. He also produced a table of cotangents and established several trigonometric identities used by later astronomers.