4:30 AM
Stars are the heavenly bodies like the sun that are extremely hot and have light of their own. Stars are made up of vast clouds of Hydrogen gas, some helium and dust. In all the stars, hydrogen atoms are continuously being converted into helium atoms and a large amount of nuclear energy in the form of heat and light is released during this process. It is this light which makes a star shine.There are billions of stars in the sky but only about 2000 stars can be seen with a naked eye on a clear moonless night. All the stars are very big in size. They appear small because they are very far-off from us. The stars twinkle at night, that is, the intensity of their light appears to increase and decrease continuously.
The stars are classified according to their physical characteristics like size, colour, brightness and temperature. The star which lies immediately above the earth's north pole and around which all other stars seem to revolve, is called pole star. The pole star appears to be stationary in the sky and does not change its position at all. It has been observed that all the stars, except the pole star, appear to move from east to west. Alpha Centaurs is the nearest star next to sun which is 4.3 light years away from us.
The stars are born, mature, grow old and finally die. The stars do not last for ever. The physical characteristics of a star like size, brightness, color and temperature also change with time.
