Vatasseri Parameshwaran Nambudiri

Vatasseri Parameshwaran Nambudiri was a 15th century astronomer and mathematician from Kerala, India.

Parameshwaran Nambudiri was born into the Vatasseri Mana (a Nambudiri Brahmin family) on the norther bank of the Nila River (Bharathapuzha) near Aswatha Gramam (near present Tirur of Malappuram district). He was a Rigvedi of the Bhrigu Gothram.

Contributions

Parameshwaran, as a result of over fifty years of systematic observations and research on 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 equinox mentioned by his disciple, Kelalloor Somayaji in his "Jyothirmeemaamsa". The 13 ½° suggested by Mujjaalakan was rectified by Parameshwaran to 15°.

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.

ee also

*Indian mathematics
*Indian astronomy

References

[http://www.namboothiri.com/articles/contributions.htm http://www.namboothiri.com/articles/contributions.htm]