Stars

Stars are bodies of plasma that undergo constant thermonuclear fusion of hydrogen into helium in their core. Characterised by their luminosity, size and spectra, stars can be organised into seven types: O,B,A,F,G,K, and M. The Sun is the closest star to Earth, this yellow dwarf has an estimated lifetime of 10 billion years. Stars have a life cycle, beginning with the gravitational collapse of gaseous nebula and ending as a white dwarf, neutron star or black hole.

Advertisement
Advertisement