_stars_ are very hot and huge heavenly objects made up of very hot gasses.they apper like'dots'becouse they are very very far away from us.their light takes million of years to reach the earth.distances of stars are,therefore,expressed in terms of a unit called,the light year.one light year is the distance travelled by light in one year.do you know ?-the speed of light is 3,00,000km/per second._sun_is the souce of energy in solar system.the radious of the sun is almost 100 times the radious of the earth and its mass about a million times the mass of earth.our _solar system_ consists of a large number of minor planets and asteroids,a hosts of comets and meteors.the gravitational pull(attraction)between the sun and these celetial bodies keeps all of them revolving around it.