Nilakantha Somayaji, also Kelallur Comatiri, ( born June 14, 1444 Trkkantiyur in Tirur, Kerala, † 1544) was an Indian mathematician, astrologer and astronomer. He belonged to the Kerala school of mathematicians and astronomers in South India. Its geo - heliocentric model (see: Tychonisches world model) corresponded to the later named after Tycho Brahe.
He was among the Nambudiri Brahmins and there to Gargya family ( Gargya gotra ), one of the box who married only among themselves. Unlike many other traditional Indian mathematicians and astronomers he made some information about himself in his works. The family followed the Ashvalayana sutra of the Rigveda. The name suffix Somayaji points out that he performed the Vedic Soma - yajna rituals - they correspond to the worship of a deity Soma ( ruler of plants and healers ). Kellalur refers to the lineage of the family Kelallur, Comatiri is a later corrupted form of Somayaji.
He studied Vedanta and astronomy with his teacher Ravi and astronomy at Damodara, son of Parameswara.
He is known for his astronomical treatise Tantrasamgraha, written in 432 Sanskrit verses in eight chapters. According to the comments of his pupil Sankara variar his main work includes a precise date of writing (1501 ). In addition to its astronomical content, it is also important for its mathematical content, among other things, it provides information on the series of discoveries Madhava, the founder of the Kerala School, which he developed himself further. His student Jyesthadeva posted a comment on his main work Tantrasamgraha.
He also wrote other astronomical treatises, as a comment on the Aryabhatiya, the main work of Aryabhata I, known Aryabhatiyaabhasya. He refers it to two independent observations of solar eclipses ( March 6, 1467 and 28 July 1501 Anantaksetra ) and refers to a book on eclipses ( Grahanirnaya ), but that is not obtained.
His treatise Golasara is about mathematical calculations in astronomy, Siddhanta Darpana treated a planetary model and Candracchayaganita deals with the calculation of the zenith distance of the moon. All these works are in Sanskrit verse.
He was married and had two sons with Arya.