What is a star?
All stars are suns – blazing fireballs of gas like our Sun.
Each star in the centre is an unusually enormous giant huge natural nuclear reactor to produces the energy that makes the star shine for billions of years before the stars finally fade away.
Many bright stars have noticeable colours – due to its temperature, the bluest stars are the hottest and the reddish stars are the coolest. Â Red and orange stars have surfaces that cooler than that of the Sun (yellow-white). Â The hottest stars of all appear blue-white :- Rigel, Sirius and Vega. (See the SkyMap from Andrew L Johnson)
Sizes and Colours.