1Supergiant

 =Super Giant = QuickFacts Largest and most Luminous star; they are very rare. Some stars are much more massive then the supergiant but they are the biggest by volume and not by mass. Super Giants have cool surfaces of 3,500-4,500K and have a radius of 1500 times the sun. Information Some stars are miles and miles across, way bigger then the sun, A Super Giant is the biggest most luminous star.Because of their extreme masses they have short lifespans of 30 million years down to a few hundred thousand years. Supergiants occur in every spectral class from young blue class O supergiants stars to highly evolved red class M supergiants.The outer hull of red glowing hydrogen and helium is inactive. Below this is a layer in which hydrogen is fusioned to helium. In the next layer helium is fusioned to carbon. So it goes on until in the core iron is made. The supergiant shines extremely bright, but only for a short time (still several hundred thousand to million years). In the end the phase in which the star fusions sulfur and silicon to iron only lasts a few days to weeks. From iron no more energy can be made. The core cools down and implodes. The following supernova (of type II) disrupts the star and leaves a tiny neutron star or a black hole behind.



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