Lagadha, an ancient Indian astronomer, is credited with developing the Nakshatra system, a set of 27 lunar mansions used for timekeeping and navigation.

Sirius, also known as the Dog Star, is the brightest star in the night sky as seen from Earth.

The Pleiades, also known as the 'Seven Sisters' or 'Krittika' in ancient Indian astronomy, is a prominent star cluster visible in the night sky.

The Saptarishi, also known as the 'Seven Sages' or 'Great Bear', is a constellation that represents a celestial chariot in ancient Indian astronomy.

The Armillary Sphere, also known as the 'Gola Yantra', was an ancient Indian astronomical instrument used to measure the positions of celestial bodies.

The Nakshatra Calendar is an ancient Indian calendar that is based on the lunar cycle and uses the positions of the moon in different constellations to determine the dates.

Ptolemy, a Greek astronomer, developed the theory of planetary motion known as the 'geocentric model', which placed the Earth at the center of the universe.

The Surya Siddhanta is an ancient Indian astronomical treatise that contains detailed observations of celestial bodies and astronomical calculations.

Aryabhata, an ancient Indian astronomer, proposed the heliocentric model, suggesting that the Earth revolves around the Sun.

Argo Navis, also known as the 'Ship Argo', is a constellation that represents a celestial boat in ancient Indian astronomy.

Varahamihira, an ancient Indian astronomer, developed the concept of 'grahas' or planets, and classified them into different categories.

The Quadrant, also known as the 'Chapa Yantra', was an ancient Indian astronomical instrument used to measure the altitude of celestial bodies.

Aryabhata, an ancient Indian astronomer, developed the concept of 'ayanamsa', the precession of the equinoxes.

Taurus, also known as the 'Bull', is a constellation that represents a celestial bull in ancient Indian astronomy.

Varahamihira, an ancient Indian astronomer, developed the concept of 'karanas', a system of astronomical units used for timekeeping.