Скачать или смотреть Do All Stars Share the Same Color? Unveiling the Spectrum of the Cosmos

No, just as different chemicals burn with different coloured flames, stars do appear in varied colours. You all enjoy campfires, right? Have you paid attention to the flame in a campfire? The central and the hottest part will appear blue and the peripheral, less hot part is orangered. The same is true with stars as well.
Stars which are relatively cooler appear red, warmer ones range from orange to yellow to white. The hottest stars glow a lighter blue and the very hottest are a darker blue colour. Contrary to our popular belief that a red face means 'heated up with anger', stars with the reddest 'face' are the coolest at about 3,000 degrees Celsius surface temperature. The hottest stars burning at 25,000 degrees Celsius or above, glow with brilliant blue light.
We have seen that stars are born in gas and dust nebulae composed of hydrogen and other elements. The stars produce different elements as they age. These different chemicals burn at different temperatures and contributes to the colour spectrum of the stars. Thus, a star's colour can give a rough idea about its relative age.
A star's visible light spectrum can denote its movement relative to us. If a star is moving away from us, its visible light shifts toward the red end of the spectrum. This is generally termed as 'redshift'. Contrarily, when a star moves towards us, its light shifts towards the blue end of the spectrum. This is termed 'blueshift'.