Brahmanda was the term used to describe the celestial sphere, encompassing all celestial bodies and phenomena.

In Indian cosmology, Mount Meru is considered the central point of the universe, around which all celestial bodies revolve.

The Rigveda, one of the four Vedas, contains hymns and verses that mention celestial bodies and astronomical phenomena, making it the earliest known astronomical treatise in India.

Navagrahas refers to the nine celestial bodies that were considered sacred in ancient India: Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn, Rahu, and Ketu.

Aryabhata, an Indian astronomer and mathematician, proposed a heliocentric model of the solar system in the 5th century CE, suggesting that the Earth and other planets revolve around the Sun.

Rasi Chakra refers to the path of the Sun through the twelve zodiac constellations, which is used in Indian astrology and astronomy to determine the positions of celestial bodies.

Varahamihira, an Indian astronomer and astrologer, developed a system of classifying stars based on their brightness and color, which was later adopted by astronomers in other parts of the world.

Nakshatra refers to the grouping of stars into constellations, which are used in Indian astrology and astronomy to determine the positions of celestial bodies and their influence on human lives.

None of the ancient Indian astronomers proposed a theory of the expansion of the universe. This concept was developed much later in the 20th century by modern astronomers.

Ayana refers to the period of time it takes for the Sun to complete one cycle through the zodiac constellations, which is approximately 26,000 years.

Brahmagupta, an Indian astronomer and mathematician, developed a method for calculating the positions of celestial bodies using trigonometry, which was later adopted by astronomers in other parts of the world.

Udaya refers to the movement of celestial bodies from east to west, which is observed as the rising of stars and planets above the horizon.

None of the ancient Indian astronomers developed a theory of planetary motion based on elliptical orbits. This concept was developed much later in the 17th century by Johannes Kepler.

Panchang refers to the period of time it takes for the Moon to complete one cycle through its phases, which is approximately 29.5 days.

Varahamihira, an Indian astronomer and astrologer, developed a system for predicting eclipses and other celestial events, which was used by astronomers for centuries.