Sunday, May 28, 2017

Big Bang Theory, Galaxies and Stars

The study about Universe is called cosmology. The theory which is the highly supported about the origin of universe is Big Bang theory. According to the big bang theory it is stated that the universe is about 13700000000 years old. The scientist who proved that universe is expanding is Edwin Hubble. The particles that is discovered farthest in universe is quasars. The mother galaxy to which the sun and solar system belongs is Milky Way. The other name of Milky Way is 'Akaashaganga'. It is estimated that Milky way has more than 20000000000 stars.

The galaxies are classified into three based on their shape.They are irregular galaxies, spiral galaxies and elliptical galaxies. It is in the irregular galaxies, that most new stars are formed. Milky Way is a spiral shaped galaxy. Elliptical galaxies are the ones that are highest in number in the universe. The place inside a galaxy where stars are formed is called Nebulae.

A group of stars appearing in the shape of animals or objects is called constellation. They help us to find direction in the dark. The nomenclature of constellations is done by International Astronomical Union. A total of 88 constellations are there. Hydra is the largest constellation. The smallest constellation is Crux. The matter is found in stars in the plasma state.

The colours of the stars indicates the temperature of stars. The two galaxies which lies nearer to milky way galaxy is Large magellanic cloud and small magellanic cloud. The star most nearer to earth is Sun.