Nilakantha Somayaji was a 15th-century Indian astronomer and mathematician who wrote the Tantrasamgraha.

The Tantrasamgraha was written in Sanskrit, the classical language of India.

The Tantrasamgraha covers a wide range of topics, including planetary motion, eclipses, and the construction of astronomical instruments.

The Tantrasamgraha describes the geocentric model of the universe, in which the Earth is at the center and the planets and stars revolve around it.

The Tantrasamgraha uses the method of epicycles and deferents to calculate the positions of the planets.

An epicycle is a small circle that a planet moves around, while the center of the epicycle moves around a larger circle called the deferent.

A deferent is a large circle that the center of an epicycle moves around.

The Tantrasamgraha explains eclipses by saying that the Moon's shadow falls on the Earth.

The Tantrasamgraha uses a combination of trial and error, mathematical calculations, and observation of the stars to construct astronomical instruments.

The armillary sphere is the most important astronomical instrument described in the Tantrasamgraha. It is a model of the universe that shows the positions of the planets, stars, and other celestial objects.

The armillary sphere is used to measure the positions of the stars, calculate the time of day, and predict eclipses.

The Tantrasamgraha is one of the most important texts in Indian astronomy, it influenced the development of astronomy in Europe, and it is still used by astronomers today.

The Tantrasamgraha was written in the year 1444.

The Tantrasamgraha has 14 chapters.

The commentary on the Tantrasamgraha written by Govinda Bhatta is called Vivarana.