How Do Stars Form? A star begins its life as a large and comparatively cool mass of gas. The contraction of this gas and the subsequent rise of temperature continues until the inside temperature of the star reaches about 1,000,000° C. The atoms move faster and that is what causes the star to gain its heat and for the temperature to rise. At this point a nuclear reaction takes place in which the nuclei of hydrogen …showed first 75 words of 429 total…

…showed last 75 words of 429 total…white, pale green or orange-red. The colour of the star tells the temperature of the star. A yellow star like the sun is reactively hot, a red star is fairly cool and a blue star is extremely hot. Colour tells more about a star then its temperature. Astronomers use the colour of a star to determine the surface temperature of the star and scientists use the basic star colour and temperature to classify the stars.