Dame Susan Jocelyn Bell-Burnell, DBE, FRS, PRSE, FRAS (born 1943)

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

Brown dwarfs are very dim, glowing objects that never gained enough mass to become fully fledged stars. In other words, the temperatures and pressures at their centres never got high enough for nuclear fusion to start.

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

Stars are formed in clouds of gas and dust, known as nebulae. Nuclear reactions at the centre (or core) of stars provides enough energy to make them shine brightly for many years. The exact lifetime of a star depends very much on its size. Very large, massive stars burn their fuel much faster than smaller stars and may only last a few hundred thousand years.