पञ्चसिद्धान्तिका (आचार्य वराहमिहिर - सूर्य, रोमक, पौलिश, वासिष्ठ एवं पितामह सिद्धान्त)

62 PAÑCASIDDHĀNTIKĀ III.21
the ancient lore. But now the summer solstice is at the beginning of Cancer and the other one at
the beginning of Capricorn. If at any time this is not conformed to, then there is a further change,
which can be seen and measured by observation and examination." (Br. Sam. III. 1-2). It is from this
that we have interpreted Punarvasu as "the point at three quarters of Punarvasu". The ancient lore
mentioned here includes Vedāṅga-Jyotiṣa and Paitāmaha Siddhānta. The Yājuṣa-Jyotiṣa says, "At the
beginning of Śraviṣṭhā the Sun and the Moon turn northward and at the middle of Āśleṣā they turn
southward, with the Sun always in the Māgha and Śrāvaṇa months, respectively" (verse 7). "When
the Sun and the Moon rise in the sky together, with Śraviṣṭhā with them, the Yuga begins then as also
the month of Māgha, the seasonal month Tapas, the bright fortnight, and the turning northward "
(verse 6). As the Paitāmaha too counts the nakṣatras of longitudes from Śraviṣṭhā and says that it is
Vyatīpātā when the sum of their longitudes is a whole revolution, we can infer that the turning
northward is at Śraviṣṭhā.
विपरीतायन(यां)तो यदार्ककाष्ठां श(शी) सविक्षेपः ।
भवति तदा व्यतिपातो दिनकृच्छशियोगचक्रार्धे ॥२२॥
22. With the Moon approaching to meet the Sun, moving in a direction
opposite to that of the Sun, when its true declination (i.e. the mean declination
plus its latitude) becomes equal to the Sun's and when the sum of their longi-
tudes is nearly six signs, then is the Vyatīpāta conforming to the definition, (i.e.
the Mahāvyatīpāta).
The minimum and sufficient conditions for the Mahāvyatīpāta are that the Sun and Moon should
have different southward or northward courses and that their true declinations must be equal, both
being north or both being south. The second part of the second condition, though not mentioned
by the verse, is implied in the requirement that the sum should be nearly six signs. Because the
northward or southward courses and the declinations depend on the tropical longitudes, we can
understand that the sum also is of the tropical longitudes (i.e. the sāyana longitudes) of the Sun and
the Moon. If this is not stated it is because during the time of the author the Ayanāṁśa, i.e. the
difference between the tropical and sidereal longitudes, was practically zero and the author
intended the work as a karaṇa not to be used for a very long time when the ayanāṁśa would become
considerable.
We have interpreted "half revolution as approximately six signs" because when the Moon has a
latitude as generally it would have, the equality in declination will happen not exactly at the sum
being six signs. Only the mean declination of the Moon will be equal to that of the Sun when the
sum is exactly six signs, as Bhāskara I says in his commentary on the Āryabhaṭīya, (Kāla, 3), "Vyatīpāta
21. Quoted by Utpala on BS 2, p.40. 22a. A.B.D. ॰यनपातो C. ॰यनभागो
21a. A1.B1.2. अश्लेषार्धा॰ b. B. पदार्क A.B. शशिसविक्षेपः
b. B. किलोकृकिरणस्य B. काष्टांशशि; C.D. काष्ठांश [श] शिरविक्षेपः
c. A. युक्तमथनं c. B. भवेति
d. A. ॰तमथनं d. A. दिनक्रछशि