Aryabhata, who lived in the 5th century CE, is widely regarded as the father of Indian astronomy due to his significant contributions to the field.

Aryabhata was the first astronomer to propose the heliocentric model of the solar system, where the Earth and other planets revolve around the Sun.

Aryabhata's astronomical treatise is titled 'Aryabhatiya', which contains his theories and calculations on various astronomical phenomena.

Aryabhata calculated the value of pi (π) to four decimal places, which is an impressive achievement considering the limited computational tools available at that time.

Brahmagupta developed the concept of 'Khagola' or spherical astronomy, which involves the study of celestial bodies on a sphere.

Varahamihira wrote the astronomical treatise 'Surya Siddhanta', which contains detailed observations and calculations related to the Sun, Moon, and other celestial bodies.

Aryabhata proposed the idea of the Earth's rotation on its axis, which was a revolutionary concept at the time.

Varahamihira developed the 'Panchasiddhantika', a treatise that compares five different astronomical systems and presents their respective theories and calculations.

Aryabhata calculated the length of the solar year with remarkable accuracy, considering the limited observational tools available at that time.

Bhaskaracharya developed the 'Lilavati', a treatise that covers various topics in arithmetic and geometry, including algebra, fractions, and mensuration.

Brahmagupta proposed the idea of the Earth's elliptical orbit around the Sun, which was a significant advancement in astronomical understanding.

Bhaskaracharya developed the 'Siddhanta Shiromani', a comprehensive treatise that covers various aspects of astronomy, including spherical astronomy, planetary motion, and eclipses.

Aryabhata calculated the circumference of the Earth with remarkable accuracy, considering the limited measurement techniques available at that time.

Brahmagupta developed the 'Karanakutuhala', a treatise that provides detailed methods for astronomical calculations, including planetary positions, eclipses, and conjunctions.

Brahmagupta proposed the idea of the precession of the equinoxes, which is the gradual shift in the position of the equinoxes over time.