The Rigveda, one of the four Vedas, contains hymns and verses that mention celestial bodies and astronomical phenomena.

The Chandra Samvat is a lunisolar calendar that follows the phases of the moon.

Aryabhata, a renowned 5th-century astronomer, is credited with introducing the concept of zero and the decimal system.

Jantar Mantar is a collection of architectural astronomical instruments built in the 18th century by Maharaja Jai Singh II.

Varahamihira, a 6th-century astrologer, wrote extensively about the Nakshatras and their astrological significance.

The quadrant, also known as the Yantra, is a device used to measure the altitude of celestial bodies.

Aryabhata made remarkable calculations of the Earth's circumference and the distance between the Earth and the Moon.

The Surya Siddhanta is an important astronomical text that provides information on astronomical instruments and their applications.

Aryabhata proposed a heliocentric model of the solar system, placing the Sun at the center.

The sundial, also known as the Gnomon, is an ancient device used to measure time based on the position of the Sun.

Bhaskara II made significant contributions to the study of planetary motion and developed trigonometric functions.

The Surya Siddhanta provides detailed information on eclipses and their prediction.

Brahmagupta developed a method for calculating the position of planets based on their mean motion.

The armillary sphere is an instrument used to study the motion of celestial bodies and their positions in the sky.

Brahmagupta made significant contributions to the study of the precession of the equinoxes and the obliquity of the ecliptic.