Red+Supergiants+4B

= = =Red SuperGiants= Definition : They are the largest stars in the Universe but not the largest when it is compared to mass.

=How a Red Giant becomes a __Red SuperGiant.__= - After a Red Giant runs out of helium in it's core, the star's core starts to fall apart and heat up. The outer layers of the star start to span and cool. As the star keeps growing it eventually becomes a __Red SuperGiant.__

__Red SuperGiants;__
 * Most are several hundred times bigger then the sun.
 * Betelgeuse and Antares are the best known examples of Red Supergiants
 * They have a slow, dense wind, that if their core's nuclear reactions slow for any reason, they shrink to a blue giant.
 * They are in the constellation Orion.
 * Any star with more then 10 solar masses after burning their hydrogen become Red SuperGiants during their helium burning phase.
 * Are often called "Hot Vacuum".
 * The mass of supergiants eventually fuse elements up to iron.
 * In the Hertzsprung-Russell Diagram the Supergiants are located the farthest right which means they have the coldest surface temperature
 * Supergiants are classified as M stars in the spectral class.

The Red SuperGiant phase is __very short__, lasting only a few thousand or a million years.



[[image:Betelgeuse.jpg width="240" height="215" caption="This is Betelgeuse. "]]
Betelgeuse is a prime example of a red Supergiant star. Its luminosity is about 10,000 times greather then the sun and its radius is about 370 time larger then the sun. Betelgeuse is located at the shoulder of Orion. a. 427 light years away from earth b. 2nd brightest star in the constellation of Orion c. 10th brightest star in the night sky.

This picture compares a supergiants size to the size of earth and jupiter. This picture obviously shows the immensity of a red supergiant