These large, swelling stars are known as red giants. But there are different ways a star’s life can end, and its fate depends on how massive the star is. A star is a luminous spheroid of plasma held together by self-gravity.

Many other stars are visible to the naked eye at night; Their immense distances from earth … The amount of material in a star (its mass) is so huge that a nuclear reaction called nuclear fusion goes on inside it. This reaction changes hydrogen to helium and gives off heat.