A History of the Kerala School of Hindu Astronomy (in Perspective) c9.s3.1

c9.s3.1

A number of original texts on astronomy, dealing with all the main topics of the subject, have been identified. Some of them, like the *Tantrasaṅgraha* of Nīlakaṇṭha Somayājī, the *Tantrasāra* of Nārāyaṇa of Peruvanam and the *Sadratnamālā* of Śaṅkara-Varman, belong to the *tantra* type of treatises which take the beginning of the Kali era as the starting point for astronomical calculations. The bulk of the original texts are, however, of the *karaṇa* type, which use some convenient contemporary date as the epoch for starting the calculations enunciated by them, a device made use of by modern astronomers as well. This date is so chosen that at the ending moment of that day, *i.e.*, at the beginning (sunrise) of the next day, the Mean Moon (*Candra*) and Mean Higher Apsis (*Candra-tuṅga*) are in the same position or very close to each other, so that the days accumulated up to the epoch (called *Khaṇḍa-dina* or *śodhya-dina*) could be subtracted in ‘full’ from the current *Kali-dina*. The Mean positions of the Sun, Moon and other planets etc. are determined very accurately for the epoch and the readings so obtained are used as zero corrections for all computations for any date after the epoch. The *Grahacāranibandhana* of Haridatta, the basic *karaṇa* text of the Parahita system of astronomy, however, uses the date of Āryabhaṭa as the epoch, and the *Dṛggaṇita* of Parameśvara, the basic text of the *Dṛk* system, uses the beginning of Kali as its epoch. Some of the *karaṇa* texts are mere manuals giving rules for specific astronomical computations while some others like the *Karaṇapaddhati* of Putumana Somayāji, are fullfledged textbooks on the subject. Among the more important *karaṇa* texts may be mentioned the *Karaṇāmṛta* of Citrabhānu, which has three commentaries, the *Karaṇasāra* with commentary, possibly, by Śaṅkara Vāriyar pupil of Nīlakaṇṭha Somayāji, the anonymous *Karaṇadarpaṇa* with three commentaries, *Karaṇottama* of Acyuta Piṣāraṭi with two commentaries, of which one is by the author himself, the anonymous *Laghukalārpaṇa* and the anonymous *Kriyāsaṅgraha*, with two commentaries. Several *karaṇa* texts have the generic title *Pañcabodha*. A dozen of them have been identified in the Inventory in Ch. V. Most of these are anonymous and only three of the authors could be identified, they being Putumana Somayāji, Puruṣottama and Kṛṣṇadāsa. These *Pañcabodha*-s have been very popular with the almanac-makers of the land and some of these claim commentaries, as well. The *Pañcabodha*-s generally contain five sections dealing with five astronomical topics. The topics treated are not, however, always the same. Thus *Pañcabodha* IV deals with *Vyatipāta*, *Chāyā*, *Maudhya*, *Śṛṅgonnati* and *Grahaṇa*, while *Pañcabodha* II deals with *Tithi*, *Vāra*, *Nakṣatra*, *Yoga* and *Karaṇa*. Again, to deal with only five topics is not always the rule in these works; the number of topics dealt with could be less or more than five. For instance, *Pañcabodha* V or *Pañcabodhasataka* of Puruṣottama, in 100 verses, contains only two sections and *Pañcabodha* I is in ten sections, dealing with *Tithinakṣatra*, *Vakyadhruva*, *Madhyama Sphuṭakriya*, *Lāṭavaidhṛta*, *Maudhya*, *suryacchāyā*, *somacchāyā*, *Śṛṅgonnati* and *Grahaṇa*. The *Bhadradipagaṇita* of Iṭakramañceri Nampūtiri and the *Gaṇitasāra* or *Pañcabodha-gaṇitasara* of Śaṅkaran Nāmpūtiri of Mahiṣamaṅgalam, both in Malayalam, are also comprehensive treatises.