Parahita school of astronomy is a system of Hindu astronomical computation widely prevalent in Kerala. It was introduced by Haridatta at a center of learning called Tirunavaya in northern Kerala, in 683 CE at a convention of astronomers who had gathered there for a 12-year festival called Mamangam. The two basic texts of the school are Grohacara nibandhana (compendium of planetary motions), and Mahamarga nibandhana (compendium of detailed processes).
Kerala had been a bastion of the Aryabhatian system of astronomy
from early times, as Haridatta bases himself on the Aryabhatian parameters, but
introduces several changes in the methods of computation. He adopted the easier
Katapayadi notation for expressing numbers in place of the complicated system
of Aryabhata. Since the system came into vogue more than 400 years after
Aryabhata, Haridata adopted that year as his epoch and, in computing the
planets, enunciated a correction called Bhatta-samskara (correction to
Aryabhata) for the years after that epoch.
A unique system of graded tables of the sine of the arcs of anomaly
and of conjunction for 24 arc-sections in a quarter of a circle introduced by the
system facilitated the computation of the true positions of the planets. These
and minor nuances in actual calculation made the system was such that even
after the advent of the drigganita system, which actually superseded the
parahita system, it was in use for fixing the auspicious time for domestic
ceremonies.
Man as Vahana of Kubera – Symbolism in Kuber Riding on Man
Pushpaka Vimana – Origin of the Flying Machine of Ravana