Notes

Star Color is determined by heat blue hottest then yellow and least hot is red
Luminosity is the true brightness of any object in space.
Hertzsprung-Russell diagram is a grapgh relating the surface temperature and absolute brightnes of stars.
Gravity is a force of attraction between objects that is due to their mass.
Nuclear Fusion is a nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy
Surface temperatures in stars is directly related to colr variations in stars
Nebula is a large cloud of gas and dust in interstellar space,where stars are born or where stars explode at the end of thier lives
Supernova is a gicantic explosion in which a massive star collapses and throws its outer layers into space
Neutron Star is a tiny star that remains after a super nova explosion
Black Hole is the final stage in the evolution of a massive star when the cores mass collapses to a point that its gravity is so stong that even light cant escape
Red Giant is the stage in a stars development when the inner helium core contracts while the outer layers of hydrogen expands
Main Sequence Star is a star in the main cycle of its life when hydrgen inside undergoes neclear fusion and gravity and pressurer are once again balancened.
Medium Star it burns for billions of years and when it runs out of hydrogen it starts to expand into a red giant
Supergiant is a very large star that is even brighger than a giant often despite being very cool.
Large Star it burns very hot and uses its energy quickly this is the only type of star that can turn into a black hole.
White Dwarf is the stage in which a star has used up its helium and its outer layers escape into space leaving behind a hot dense core that contracts