Aryabhata is widely regarded as the father of Indian astronomy due to his significant contributions to the field. He lived in the 5th century CE and is known for his work on astronomy, mathematics, and astrology.

Aryabhata proposed the heliocentric model of the solar system, where the Sun is at the center and the planets revolve around it. This model was later adopted by Nicolaus Copernicus in the 16th century.

Maharaja Jai Singh II built five astronomical observatories called Jantar Mantar in various cities across India. These observatories were used to make accurate astronomical observations and study the movement of celestial bodies.

Varahamihira, an Indian astronomer and astrologer, developed the concept of 'kalpas' and 'yugas' to describe the cyclical nature of the universe. He believed that the universe goes through a series of cycles, each consisting of four yugas: Satya Yuga, Treta Yuga, Dwapara Yuga, and Kali Yuga.

Astrosat is an Indian satellite launched in 2017 to study the universe's X-ray emissions. It is the first dedicated Indian astronomy satellite and carries five X-ray instruments to observe celestial objects in various energy bands.

Subrahmanyan Chandrasekhar, an Indian-American astrophysicist, proposed the idea of an expanding universe in the early 20th century. His work on the theory of stellar evolution and black holes earned him the Nobel Prize in Physics in 1983.

The Himalayan Chandra Telescope (HCT) is an Indian telescope located at the Devasthal Observatory in Uttarakhand. It is a 2-meter optical-infrared telescope used to study various astronomical objects, including galaxies, stars, and planets.

George Smoot, an American astrophysicist of Indian origin, played a significant role in the discovery of the cosmic microwave background radiation (CMB). The CMB is the remnant radiation from the Big Bang, and its discovery provided strong evidence for the Big Bang theory.

Aditya-L1 is an Indian space mission aimed at studying the Sun's corona. It is scheduled to be launched in 2023 and will be placed in a halo orbit around the Sun's L1 Lagrange point, allowing it to continuously observe the Sun's corona.

Arthur Eddington, an English astronomer of Indian origin, developed the theory of 'stellar pulsation' to explain the variability of certain stars. His work on the internal structure of stars and the theory of relativity earned him the Nobel Prize in Physics in 1922.

GSAT-30 is an Indian satellite launched in 2019 to study the Earth's magnetosphere and ionosphere. It carries a suite of instruments to measure various parameters related to the Earth's magnetic field, plasma environment, and ionosphere.

Harlow Shapley, an American astronomer of Indian origin, proposed the idea of a 'pulsating universe' in the early 20th century. He suggested that the universe undergoes a cycle of expansion and contraction, similar to the pulsation of a star.

INSAT-3DR is an Indian satellite launched in 2018 to study the Earth's atmosphere and climate. It carries a variety of instruments to measure various atmospheric parameters, including temperature, humidity, wind speed, and aerosol concentration.

Subrahmanyan Chandrasekhar, an Indian-American astrophysicist, developed the theory of 'gravitational collapse' to explain the formation of stars. His work on the theory of stellar evolution and black holes earned him the Nobel Prize in Physics in 1983.

Resourcesat-2A is an Indian satellite launched in 2016 to study the Earth's surface and natural resources. It carries a variety of sensors to collect data on land use, agriculture, forestry, water resources, and mineral exploration.