The relationship between white dwarfs, red dwarfs, white giants, red giants and stars, are there any other color classifications?

White dwarfs, red dwarfs, white giants and red giants are all stars, and some of them used to be stars.

Look at the picture. If a star is formed with a small mass, larger than a brown dwarf (also called a brown dwarf), but smaller than the sun, and its surface temperature is above 2000 degrees and below 5000 degrees, and it is red, it is a red dwarf. The life span of red dwarfs is very long, reaching tens to hundreds of billions of years.

A white dwarf is the core of a small-mass star, whose mass is similar to that of the sun at the end of evolution. Because of its extremely high surface temperature and extremely small scale, it is called a white dwarf.

In astronomy, there is no such thing as a white giant. But it can be understood as a star with a mass greater than that of the sun in the main sequence stage. It should be a white star with a surface temperature of 8000- 10000 degrees and a diameter much larger than that of the sun.

Red giant is a red star whose mass is greater than or equal to the mass of the sun and its surface temperature drops in its later evolution period. If it is a massive star, its diameter will increase in the later stage of evolution, which is called red Supergiant star.

In addition, if the mass of the star is more than 7 times that of the sun when it is formed, then the surface temperature can reach more than1.5000 degrees in the main sequence star stage, and it is blue, which is called blue giant.