Life Cycle

Red Supergiants

The Orion region showing the red supergiant Betelgeuse
By Rogelio Bernal Andreo CC BY-SA 3.0

Red supergiants have the largest radius of all known stars. They have low surface temperatures (for stars!) of below 4,100 K. This causes them to shine with a red colour. The star Betelgeuse in the constellation of Orion is a red supergiant.

Main Sequence

Main sequence stars fuse hydrogen into helium. Stars live the majority (about 90%) of their lives in this stage of their evolution. Our Sun is thought to be about 5 billion years into its 10 billion year main-sequence lifetime.

Type Ia Supernovae

Artists impression of Type Ia supernovae
Credit: NASA/CXC/M. Weiss

Type Ia supernovae are also known as thermonuclear supernovae. They involve a binary (or double) star system. Where one star is a white dwarf, and the other is usually a star like our Sun or a huge red giant star.