Introduction

During the time of Brahmagupta, the star Chitra Spica was situated at 183 degrees; that is, from the time of the author of the Surya Siddhanta and Varaha, the star Chitra advanced three degrees eastward. Therefore, Brahmagupta was born 215 years after Varahamihiracharya, specifically in the Shaka year 421 approx. 499 CE.

It is said that at the court of the Persian Shah Naushikhan Khosrow I, there was a minister named "Buzurjmeher." This Shah reigned from 534 CE to 590 CE. Because there is some slight similarity between this name and the name Varahamihira, some might speculate that he was a member of Shah Naushikhan's court. If such people were to learn the facts, their misconception would be removed, as it is believed that the Panchatantra of Vishnusharma was translated into the Persian language by the order of this very minister. Furthermore, another reason is that Vishnusharma has written the name of Varahamihiracharya within the Panchatantra; how then could Varahamihiracharya have belonged to the time of Naushikhan?

Varahamihiracharya, in his work Brihat Jataka, has listed the names of many astronomers who preceded him. For example: Maya, Yavana, Manittha, Shakti, Satya, Bali, Vishnugupta, Devaswami, Siddhasena, Jivasharma, Prithuyasha, and so on. Varaha also acknowledged that the Ionians original: "Yavanas" and Greeks possessed special expertise in astronomy. He says:

"The Yavanas are indeed foreigners original: "Mlechha", yet this science is well-established among them. Therefore, even they are honored like sages; how much more so then a Brahmin who is a knower of the divine science?"

Among the "Mlechha" (those of foreign conduct) Yavanas, there is a specialized study of this science (predictive astrology). For this reason, they are worthy of worship like sages; if the knower of the scripture is a Brahmin, then what more need be said? Seeing this statement, it is estimated that Varaha also had contact with Egyptian astronomers.

Before determining the time of Aryabhata, it is necessary to write something regarding the Precession of the Equinoxes original: "Ayanamsha". Just as our astronomers do not agree on the measurement of the year, their views on the Precession are not uniform. Even the primary ancient astronomers, such as the author of the Parashari, considered the state of the Precession to be fluctuating. However, Vishnuchandra, the author of the Vashistha Siddhanta, was the first to reveal the revolution of the celestial node the point where the ecliptic and equator intersect like a circumference.

According to the view of Aryabhata, in one Kalpa an eon of 4,320,000,000 years, there are 1,582,237,500,000 sidereal risings; therefore, in these many years, there are 157,791,750,000 days. Many astronomers who came later have used the measurements of the year determined by the Aryabhatas in their own books. The author of the Brahma Siddhanta has written that in one Kalpa, there are "fifteen trillion, eight hundred twenty-two billion, three hundred sixty-four million, five hundred thousand" original Sanskrit numeral: "privatavichutustayasharabdhirasagunayamadvivasutithayah" sidereal risings. Brahmagupta, the author of the Brahma Sphuta Siddhanta, has also written this. As follows:

"The planetary mathematics spoken by Brahma, which had become decayed over a long period of time, is now being stated clearly by Brahmagupta, the son of Jishnu. I shall explain the defects, such as the differences in the start of the Yugas, of those whose vision is blocked by the veil of ignorance and who speak differently from the Brahma Siddhanta."