Question

What does the colour of a star indicate?

Answer 1

Hint:Stars have various colors, which are due to the abundance of the temperature their surface maintains. It is the temperature that explains the color of the stars. As a star age, it provides different chemicals which burn at various temperatures. We can utilize a star's color to explain its relative age.

Complete step-by-step solution:
There are two primary reasons for different star colors:
Temperature – Cooler stars are red, warmer ones are orange through yellow and white. The hottest stars shine with blue light
Age – Throughout most of a star's lifetime, it is lighting hydrogen at its core, which generates lots of energy and thus appears blue. As stars age, they go out of hydrogen to burn, reducing the energy they emit. Thus, younger stars can look bluer while older ones look redder, and in this way, a star's color can inform us something about that star's age.
Class O stars, blue, are the hottest, and class M stars, red color, are the coldest. Thus, it is helpful to understand the reason blue stars are hot and red ones are excellent:
The object's temperature is a direct estimation of the amount of motion inside it. The warmer the star, the faster its particles travel, and the more energy they emit.
Cool stars emit most of their energy in the electromagnetic spectrum's red and infrared region, which suggests smaller wavelengths and less energy.
Thus, they look red, while hot stars — in which particles move much more quickly — emit more energy and thus emit predominantly at blue and ultraviolet wavelengths, making them appear blue or white.
The mix of other elements contributes to the color spectrum of the stars they create. Stars exist in various colors: red, orange, yellow, green, white, and blue, with red being the most extraordinary and the hottest. Blue stars are hottest because their nuclear fusion remains fast & the photons of light produced from fusion have more energy.

Note:As the color of the stars is because of the variation of temperatures, similarly, the appearance of the stars is due to the stability of two forces. One is gravity that needs to compress the star into its center. Another one is the enlargement which resists the compression. Expansion occurs due to the nuclear fusion reaction in the nucleus.