Life Cycle
Main Sequence
Stars in the main-sequence stage give out energy as light and heat. This energy is released by nuclear fusion reactions deep in their cores. The reactions fuse hydrogen nuclei to create helium. Stars spend about 90% of their lives in this stage. Our Sun is about 5,000 million years into its 10,000 million year main-sequence.
Type Ia Supernovae
Jocelyn Bell-Burnell

Credit: Wikimedia (User: Anrie)
Occupation: Astrophysicist
Year born: 1943
Research Areas: Radio-Astronomy, Pulsars
Pulsar

Credit: Science@NASA
Brown Dwarf

An artist's impression of a Brown Dwarf
Credit: NASA/JPL-Caltech
Credit: NASA/JPL-Caltech
Black Holes

Image from the EHT Consortium/ESO
Neutron Stars

Credit: Casey Reed/Penn State University
A neutron star is the collapsed core of a massive star. It is what is left of the star, after a supernova explosion.
White Dwarf

Credit: NASA, S. Charbinet
Supernovae

Credit: NASA, ESA, The Hubble Key Project Team,
and The High-Z Supernova Search Team