Aryabhata, a renowned astronomer and mathematician from ancient India, proposed the heliocentric model of the solar system in the 5th century CE, where the Sun is at the center and the planets revolve around it.

The Surya Siddhanta is an important astronomical text from ancient India, believed to have been composed between the 4th and 5th centuries CE. It provides comprehensive information on astronomy, including planetary positions, eclipses, and the calculation of time.

Bhaskara II, an eminent mathematician and astronomer from ancient India, made significant contributions to trigonometry. He developed the sine function and formulated trigonometric identities, which are still used in modern mathematics.

The Jantar Mantar is a collection of astronomical observatories built by Maharaja Jai Singh II in the 18th century CE. It consists of several instruments used for observing celestial bodies and measuring time, and is still used by astronomers today.

Aryabhata, in his treatise the 'Aryabhatiya', proposed the idea that the Earth is round and rotates on its axis, challenging the prevailing belief of a flat Earth.

The quadrant, also known as the 'Yastiyantra', was an astronomical instrument used in ancient India to measure the altitude of celestial bodies above the horizon.

Varahamihira, in his work the 'Brihat Samhita', developed a method for calculating the time of eclipses, demonstrating his expertise in astronomical calculations.

The armillary sphere, also known as the 'Gola Yantra', was an astronomical instrument used in ancient India to measure the position of stars and planets in the sky.

Bhaskara II, in his work the 'Siddhanta Shiromani', proposed the idea that the planets move in elliptical orbits around the Sun, a concept later refined by Johannes Kepler.

The sundial, also known as the 'Gnomon', was an astronomical instrument used in ancient India to measure the time of day by observing the position of the Sun.

Aryabhata, in his treatise the 'Aryabhatiya', developed a method for calculating the distance to the Moon, demonstrating his understanding of celestial distances.

The dioptra, also known as the 'Yasti', was an astronomical instrument used in ancient India to measure the distance between two celestial bodies.

Aryabhata, in his treatise the 'Aryabhatiya', proposed the idea that the universe is infinite and contains countless stars and galaxies, challenging the prevailing belief of a finite universe.

The sextant, also known as the 'Sashtiamsa Yantra', was an astronomical instrument used in ancient India to measure the angle between two celestial bodies.

Varahamihira, in his work the 'Brihat Samhita', developed a method for calculating the time of sunrise and sunset, demonstrating his expertise in astronomical calculations.