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 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 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.

A neutron star is the incredibly compact core that remains after a supernova event.