A History of the Kerala School of Hindu Astronomy (in Perspective) c9.s4.1

c9.s4.1

The fact that the calculation of the exact *tithi* (lunar day) and *nakṣatra* (asterism) at any moment depends upon the accurate knowledge of the Moon at that moment and that all the three, *viz.*, *tithi*, *nakṣatra* and Moon, are always required for the fixation of social and religious functions, in horoscopy and in the computation of eclipses etc. is enough to explain the importance given to the computation of the Moon. But the fast motion of the Moon, amounting to about 13 degrees a day, and the consequent quick change of its position during the same day, required special consideration in its correct computation. A good number of *karaṇa* texts, devoted specifically for the computation of the Moon, have, therefore, been composed. Among the more important manuals of this type may be mentioned the *Candra-sphuṭagaṇita* with a commentary and a super-commentary, *Candra-sūryasphuṭa-gaṇita*, *Candra-sphuṭādi-gaṇita*, *Śuddha-candra-kriyā-gaṇita*, *Śrāddha-candrādi-gaṇita* and *Sūkṣma-candra-sphuṭādi-gaṇita*, all anonymous.