Aryabhata, a renowned Indian astronomer and mathematician, proposed the heliocentric model in his text, the Aryabhatiya, around the 5th century CE. This model placed the Sun at the center of the solar system, with the Earth and other planets revolving around it.

Ancient Indian astronomers primarily used the armillary sphere, a spherical model representing the celestial sphere, to observe and study the positions and movements of celestial bodies.

The Surya Siddhanta, an influential astronomical text from ancient India, is known for its detailed descriptions of astronomical phenomena, including planetary motions, eclipses, and the calculation of time.

Brahmagupta, a renowned Indian astronomer and mathematician, is credited with developing the concept of zero and its use in the decimal system in the 7th century CE.

The Jantar Mantar observatories were primarily designed for observing celestial objects, such as the Sun, Moon, and stars, to study their positions, movements, and astronomical phenomena.

Bhaskara II, a renowned Indian astronomer and mathematician, made significant contributions to the field of trigonometry, developing various trigonometric formulas and identities.

Ancient Indian astronomers primarily used trigonometric calculations to determine the positions of celestial bodies, employing various trigonometric formulas and techniques.

The Surya Siddhanta, an influential astronomical text from ancient India, provides detailed descriptions of planetary motions and methods for calculating eclipses, demonstrating the advanced astronomical knowledge of ancient Indian astronomers.

The Nakshatras, a system of lunar mansions, were primarily used in ancient Indian astronomy to determine astrological influences, such as the positions of planets and stars relative to the Moon, for astrological purposes.

Brahmagupta, a renowned Indian astronomer and mathematician, made significant contributions to the field of algebra, developing various algebraic formulas and techniques.

The Panchang, a traditional Indian calendar system, was primarily used to determine astrological influences, such as the positions of planets and stars relative to the Moon, for astrological purposes.

The Surya Siddhanta, an influential astronomical text from ancient India, provides detailed descriptions of various astronomical instruments, such as the armillary sphere and sundial, and their uses in astronomical observations.

The Jyotishastra, a branch of ancient Indian astronomy, was primarily concerned with determining astrological influences, such as the positions of planets and stars relative to the Moon, for astrological purposes.

Bhaskara II, a renowned Indian astronomer and mathematician, made significant contributions to the field of geometry, developing various geometric formulas and techniques.