What is a star which is dying?

A dying star is a called a "red giant." This is a star whose diameter is many times greater than that of the sun (despite the fact that it is cooler). The brightness of a red giant comes from its shell, which is still burning hydrogen. read more

How the star dies, however, depends on what type of star it is. Stars Like the Sun When the core runs out of hydrogen fuel, it will contract under the weight of gravity. read more

A dying star is a star that no longer has enough hydrogen nuclei (free protons) to sustain the thermonuclear fusion reactions that permit its core to combine four hydrogen nuclei to form one helium nucleus. Astrophysicists have developed excellent understanding of the death of stars, although new details do continue to emerge. read more