Changes

The stars with the greatest luminosity and mass are generally referred to as '''hypergiants''' (luminosity class 0).  Although the term is used loosely, the criterion used to separate supergiants from hypergiants is that the latter are stars with an absolute magnitude greater then -7.  Because of this, hypergiants do not have to be the more massive than other supergiants, but the most massive stars are still generally seen as hypergiants.<ref>http://adsabs.harvard.edu/abs/1998A%26ARv...8..145D</ref> Like supergiants, these most luminious of stars can have a spectral type ranging from class A to M.

The stars with the greatest luminosity and mass are generally referred to as '''hypergiants''' (luminosity class 0).  Although the term is used loosely, the criterion used to separate supergiants from hypergiants is that the latter are stars with an absolute magnitude greater then -7.  Because of this, hypergiants do not have to be the more massive than other supergiants, but the most massive stars are still generally seen as hypergiants.<ref>http://adsabs.harvard.edu/abs/1998A%26ARv...8..145D</ref> Like supergiants, these most luminious of stars can have a spectral type ranging from class A to M.

Hypergiants are so luminous that they sit very close to the point where radiation from the interior of the star would overcome the inward force of gravity.  This theoretical upper limit for the luminosity of a star is called the Eddington limit.  Any star that exceeds this limit will be blown apart from its own immense radiation.

Hypergiants are so luminous that they sit very close to the point where radiation from the interior of the star would overcome the inward force of gravity.  This theoretical upper limit for the luminosity of a star is called the '''Eddington limit'''.  Any star that exceeds this limit will be blown apart from its own immense radiation.

==End of Supergiants==

==End of Supergiants==