Aryabhata, who lived in the 5th century CE, is considered the father of Indian astronomy. He made significant contributions to the understanding of astronomy, mathematics, and physics.

Maharaja Jai Singh II constructed five Jantar Mantars, astronomical observatories, in various cities across India. These observatories were used for astronomical observations and calculations.

Aryabhata proposed the heliocentric model of the solar system in the 5th century CE, centuries before Copernicus presented it in the West.

Brahmagupta, an Indian astronomer and mathematician, developed the concept of zero and the decimal system in the 7th century CE.

Bhaskara II, an Indian astronomer and mathematician, calculated the value of pi (π) to an accuracy of four decimal places in the 12th century CE.

Aryabhata developed the trigonometric functions of sine, cosine, and tangent in the 5th century CE.

Varahamihira, an Indian astronomer and astrologer, wrote the astronomical treatise 'Surya Siddhanta' in the 6th century CE.

Aryabhata developed the concept of the precession of the equinoxes, the gradual shift in the position of the equinoxes over time, in the 5th century CE.

Aryabhata calculated the length of the solar year to be 365.25875 days, which is very close to the modern value of 365.24219 days.

Varahamihira wrote the astronomical treatise 'Panchasiddhantika' in the 6th century CE, which compared five different astronomical systems.

Varahamihira developed the concept of the zodiac and the twelve signs of the zodiac in the 6th century CE.

Bhaskara II wrote the astronomical treatise 'Lilavati' in the 12th century CE, which focused on arithmetic and geometry.

Varahamihira developed the concept of the nine planets, including Rahu and Ketu, in Indian astronomy in the 6th century CE.

Bhaskara II wrote the astronomical treatise 'Siddhānta Shiromani' in the 12th century CE, which became a standard textbook in Indian astronomy.