Brahmasphutasiddhanta (Complete Sanskrit Text) (1966) - Page 25

As Kamalakara says, God Sūrya himself is its author. It is a matter of surprise that in this (Sūrya Siddhānta), the calculation of the ayanāṃśa precession of the equinoxes is performed:

"Thirty times in a cycle, the circle of stars moves backward.
That, multiplied and divided by the terrestrial days, is obtained from the Ahargaṇa."
"The degrees obtained by multiplying by three and dividing by ten are to be known as ayanāṃśa.
From the planet corrected by that, the declination, shadow, half-day duration, etc. [are calculated]."

This has been done. But Brahmagupta, the creator of the Brahmasphuṭasiddhānta, did not even discuss that (ayanāṃśa). How Brahmagupta did not discuss it is not known. In the chapter on rising and setting in the Sūrya Siddhānta, "Abhijit, Brahmahridayam, Swati, Vaishnava, Vasava," etc., have been mentioned by God Sūrya as stars that are always visible. In the Sudhāvarṣiṇī commentary on this verse, it is written that "without knowledge of the country, there is no knowledge of the always-visible stars, and in the equator, even the northern pole is invisible; therefore, this verse was inserted by someone ignorant of the sphere." That is not correct. Regarding the Pāta moment of eclipse or planetary node, the result of the time of the Pāta is:

The time between the beginning and the end should be known as very fierce.

It is like a blazing fire and is condemned for all actions.

As long as the distance between the discs of the Sun and Moon remains in one line,

That duration destroys all actions.

Through bathing, charity, chanting, śrāddha ancestral rite, vows, and fire sacrifices,

Great merit is obtained by knowing the time [of the Pāta].

By this, the time of the Pāta is said to be destructive to all actions. People obtain great welfare by performing bathing, charity, etc., during the Pāta time. And also:

When the Sun and Moon have equal declination near the equinox,

Then the Pāta occurs twice; if there is a reversal, it does not exist.

By this, an unprecedented subject is mentioned: when the declination of the Sun and Moon is equal near the junction of the two hemispheres, the Pāta occurs twice in a short time. When there is no equality of declination near the solar solstice junction, there is no equality of declination for a long time. The result of the Pāta time is mentioned in the Brahmasphuṭasiddhānta just as in the Sūrya Siddhānta. In the Siddhāntaśekhara, [it describes] how long the Pāta effect lasts.