Vatasseri Parameshwaran Nambudiri
Vatasseri Parameshwaran Nambudiri was a 15th-century astronomer and mathematician from Kerala, India.
Origins
Parameshwaran Nambudiri (1360-1450 CE) was born into the Vatasseri Mana family on the northern bank of the Nila River (Bharathapuzha) near Aswatha Gramam (near present Tirur of Malappuram district). He was a Rigvedi of the Bhrigu Gothram. His son Damodharan Nambhudiri was a well known Indian mathematician. They were members of the Kerala School of Mathematics and Astronomy founded by Madava (who is known for the Madhava series, which he discovered about two centuries before Gregory and Leibniz did).
Contributions
Parameshwaran was a student of Madavan Nambudiri of Sangamagrama, modern day Irinjalakuda. As a result of over fifty years of systematic observations and research on the movements of celestial bodies, estimated the error factor and established a new method called Drig Sidhham. This method is explained in his famous work Driganitham (1431 AD).
Another of his contribution was a correction to the angle of precision of the equinox mentioned by his disciple, Kelalloor Somayaji in his Jyothirmeemaamsa. The 13 ½° suggested by Mujjaalakan was rectified by Parameshwaran to 15°.
Publications
Other works include the 3-volume, 302 verse Gola Deepika (1443 AD) explaining the stars and earth in very simple terms, Jaathaka Padhhathy in 41 verses, Soorya Sidhhantha Vivaranam, Grahana Mandanam, Grahanaashtakam, Vyatheepaathaashtaka Vrththi in 500 verses.
He has written superb commentaries such as Sidhhantha Deepika on Govindaswamy's Mahaa Bhaaskareeyam; Karma Deepika or Bhata Deepika on Aarya Bhateeyam; Muhoortha Rathna Vyaakhyaa on Govindaswamy's Muhoortha Rathnam; Leelavathee Vyaakhyaa on the famous mathematical treatise, Leelavathy of Bhaskara II; Laghu Bhaaskareeya Vyaakhyaa on Laghu Bhaaskareeyam of Bhaskara I; Jaathaka Karma Padhhathee Vyaakhyaa on Sreepathy's 8-chapter work on Jyothisham; the one on Laghu Maanasam of Mujjaalakan; Jaathakaadesa Vyaakhyaa; and Prasna-Nashta Panchaasikaavrthy also called Paarameswari based on the work of Prathhuyasass, son of Varaahamihiran.
