Life Cycle of a Star

Jessie Richardson

Birth of a Star

A star start from a nebula. This nebula is of high density and begins to pull inward of its self.

Once in Main Sequence

A star's duration on the Main Sequence is the longest and calmest phase in its life.

Typically a star spend 90% of its life in this stage.

A star's lengh of time in this phase is dictated by mass. Large mass stars remain on the Main Sequence a much shorter period, than small mass stars do.

Hydrogen Burning

Hydrogen burning is when the star burns its Hydrogen to create Helium.This happen during the Main Sequence through many nuclear reactions. When there is no Hydrogen the star starts to burn Helium to create heavier elements like Carbon.

Becoming a Red Giant

This is one of the stars final stages of life. The star will expand and become dimmer and cooler. This is a fairly short period in stellar evolution.


During a Supernova the light from the star will shine brighter than a galaxy. This is the stage where the outer layer of the red giant are blown of. This outer layer will then become a planetary nebula it is about 80% of the star. It will provide new opportunities for life when it has drifted from the star.

White Dwarf

This is the last stage of a stars life. After the gas and dust produced by the supernova has drifted away, all thats left is a hot, very dense star. Eventually this star will burn out completely and become a black dwarf.