Astronomy and Cosmology

Author(s): L C Jain
Publisher: Rajasthan Prakrit Bharti Sansthan Jaipur

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A tithi is measured in ghați and pala. A muhūrta equals 48 minutes, or 2 ghatis, or 120 palas. A day of 24 hours equals 30 muhurtas. Thus a ghaţi is of 24 minutes. The origin of time is regarded from the instant of sun-rise on a particular day. In the pañcānga, if the time shown for the tithi is 5 ghatis 12 palas, it will signify that the tithi will end at 5 ghatis 12 palas, after the sunrise for the day. The tithis are of unequal duration, due to non-uniform motion of the sun and the moon. The Kṛşna paksa and śukla pakşa, each consists of 15 tithis.
Vara: Any day of the week is called vāra, and it begins with the rise of the sun and ends after 24 hours.
Nakşatra: In Jaina calendar the ecliptic is divided into 28 unequal parts, and each is called a nakṣatra. The sidereal period of the moon is about 27 days, a nakşatra is described in about a day by the moon, Apart from the 27 nakṣatras of the Hindu astronomy, the Jainas added Abhijit nakşatra. When the moon is in Abhijit, it means that duration itself lasts as the Abhijit nakşatra name. The time of birth goes with the moon's position in a nakşatra. where as the time of a season goes with the sun's position in a nakṣatra. The instants, when the moon crosses or transits from one nakşatra to another are shown in the Pancanga.
GRADUATION OF CELESTIAL SPHERE
The Jaina calendar divides the whole stretch of the heaven into 54900 celestial parts (gagana khanḍas) which may be kept equivalent to 3600 of the modern celestial or armillary sphere. A measure of a sign of Zodiac is 300, and that will be equivalent to 4575 celestial parts (abbr. c. p.) The correspondence between stretches of the nakṣatra and Zodiacal constellations in terms of celestial parts and the duration for which they remain with the moon and the sun work out as follows,69
69.
Cf. T. P,. II, ch. 7, specially, vv. 478-488. Cf. also S. P., op. cit.
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