When we look at the clear starry sky, the first thing we notice is that some stars are better seen than others. With the naked eye we can see up to the sixth magnitude, and then notice that the stars are of different colors. There are shades, but the stars have three basic colors: red, yellow, and blue. Red stars are the coldest and blue or white are the warmest. We can also determine the age of a star by its color. Young stars are hot blue or white, and old ones are relatively cool and red. The colors stars depends on the temperature on its surface, and the temperature on the surface depends on the age and mass of the star. It can be from a thousand kelvins to hundreds of thousands of kelvins.
According to the appearance of the color spectrum, we have different classes: O, B, A, F, G, K, M. We obtain these classes using a spectrograph. This device uses a prism to separate light into a spectrum. This gives us more precise data about the star we are analyzing. The stars of groups O, B, and A are mostly white or light blue, the stars of class F are yellowish, the stars of class G belong to the yellow stars, the stars to orange, and to the others the red stars. Colors stars are multicolored.
Join our Facebook group : Learn Astronomy and Astrophotography … HERE
Europe : Our recommendation is (click on image):
USA : Our recommendation is (click on image):
Equipment for astronomy in Europe. Therefore, go here:
Equipment for astronomy in USA. Therefore, go here:
TRANSIT OF MERCURY AND VENUS SPACE