Life Cycle of a Small Mass Star

Protostar

• Stars appear to form in clusters inside giant molecular clouds of gas and dust. When areas within these clouds collapse due to gravity, they heat up in intensity, creating a swirling, super-hot sphere of gas called a protostar.

The Core

• As the protostar continues to gravitationally collapse and contract, it begins to convert hydrogen to helium at its core and enters the next cycle of its life, that of a main sequence star.

Main Sequence Stars

• Ninety percent of a low-mass star's life will be spent as a main sequence star. During this stage, it busily fuses hydrogen to helium. The temperature at its core will remain a steady 15 million degrees Kelvin.

Red Giant

• Billions of years later, as the low-mass main-sequence star starts to run out of energy at its core, it begins to expand, becoming more luminous and redder in color. Though the aging star has become larger, it has less mass, and its outer shell has begun to cool.

White Dwarf

• Eventually, as more and more mass is lost over the next few tens of thousands of years, all that will remain of the bloated red giant will be its hot core of carbon. This carbon core will cool and dim and become a white dwarf, essentially a "dead" star, devoid of nuclear fusion.