Aryabhata (476-550 CE) is widely regarded as the father of Indian astronomy for his significant contributions to the field.

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

Brahmagupta (598-668 CE) developed the concept of the zero digit and the decimal system, revolutionizing the field of mathematics.

Bhaskara II (1114-1185 CE) calculated the value of pi (π) to four decimal places, demonstrating his mathematical prowess.

Varahamihira (505-587 CE) wrote the influential astronomical treatise 'Surya Siddhanta,' which became a standard text for centuries.

Varahamihira developed the concept of 'grahas' or celestial bodies, including planets, moons, and comets, in his astronomical studies.

Brahmagupta proposed the theory of 'kendraka' or the central force holding the universe together, demonstrating his understanding of gravitational forces.

Aryabhata calculated the Earth's circumference with remarkable accuracy, considering the limited resources and technology available at the time.

Varahamihira developed the concept of 'tithis' or lunar days and 'pakshas' or lunar fortnights, which are crucial for the Hindu calendar.

Varahamihira wrote the astronomical treatise 'Pancasiddhantika,' which synthesized the knowledge from five different astronomical traditions.

Varahamihira proposed the idea of 'yugas' or cosmic cycles in Indian cosmology, including the Satya Yuga, Treta Yuga, Dwapara Yuga, and Kali Yuga.

Varahamihira developed the concept of 'bhavana' or mental visualization in astronomy, emphasizing the importance of observation and imagination.

Bhaskara II wrote the astronomical treatise 'Lilavati,' which focused on mathematical astronomy and included topics like planetary motion and eclipses.

Brahmagupta developed the concept of 'ganita' or mathematics in astronomy, emphasizing the use of mathematical techniques to solve astronomical problems.

Varahamihira proposed the idea of 'kshetraja' or the Earth's shadow during a lunar eclipse, demonstrating his understanding of celestial phenomena.