Varahamihira’s wrote the book Pancha-Siddhantika, on the Five Canons (Astronomical Treatise) dated ca. 575 CE gives us information about older Indian texts which are now lost. The work is a treatise on mathematical astronomy and it summarises five earlier astronomical treatises, namely the Surya Siddhanta, Romaka Siddhanta, Paulisa Siddhanta, Vasishtha Siddhanta and Paitamaha Siddhantas. It is a compendium of Vedanga Jyotisha as well as Hellenistic astronomy (including Greek, Egyptian and Roman elements).
He was the first one to mention in his work Pancha Siddhantika that the ayanamsa, or the shifting of the equinox is 50.32 seconds.
The 11th century Iranian scholar Alberuni also described the details of “The Five Astronomical Canons”:
- “They [the Indians] have 5 Siddhāntas:
- Sūrya-Siddhānta, ie. the Siddhānta of the Sun, thought to be composed by Lāṭadeva,but actually composed by Mayasura also known as Mamuni Mayan as stated in the text itself.
- Vasishtha-siddhānta, so called from one of the stars of the Great Bear, composed by Vishnucandra,
- Paulisa-siddhānta, so called from Pulisa, the Greek, from the city of Saintra, which is supposed to be Alexandria, composed by Pulisa.
- Romaka-siddhānta, so called from the Rūm, ie. the subjects of the Roman Empire, composed by Śrīsheṇa.
Varāhamihira called Varaha or Mihir, was an Indian astronomer, mathematician, and astrologer who lived in Ujjain. He was born in Avanti region, roughly corresponding to modern-day Malwa, to Adityadasa, who was himself an astronomer.
According to one of his own works, he was educated at Kapitthaka. He is considered to be one of the nine jewels (Navaratnas) of the court of legendary ruler Yashodharman Vikramaditya of Malwa.