What is the difference in the fate of a small star and a very massive star?

1 Answer
Dec 21, 2015

Sun will transform into a White Dwarf.


A main sequence Star much like our Sun will burn its fuel slowly throughout its lifetime. Currently the Sun is fusing Hydrogen to Helium. It has been doing this for about 4.5 Billion years and it will continue to burn Hydrogen for the next 4.5 Billion years until it cannot further burn Hydrogen and all that is left in its core is Helium. At this point, the Sun will expand its outer layers transforming into a Red-Giant. In this stage the Sun will burn Helium into Carbon for the next 100 million years until it runs out of Helium.

At this stage the Sun will have only Carbon in its core and will not be dense enough to transform it into other heavier elements. The Sun will once again rearrange itself and shed its outer layers into Space forming a planetary nebula with a White Dwarf at the center of it. This is pretty much life of a Normal Sized star. It is estimated that after 100 Billion years after the formation of White dwarf that the White Dwarf will cool down and transform into a Black Dwarf, A dead Star with no Radiation, but this is completely hypothetical as the Universe is not old enough.

A bigger Star, much bigger than our Sun, Super Giants, Hyper Giants, will burn their Hydrogen much more faster than our Sun given their Size and higher temperature range. The will burn hydrogen to Helium in about a few to a 100 million years and then transform into Red-Supergiants. At this point they will burn Helium to Carbon and after that carbon to other heavier elements like Iron, Silicon and Nitrogen etc. Iron is the most stable element, after these massive stars have only iron in their cores, the fusion reactions will stop and there will be no outward pressure to balance the inward acting gravity and the Star will collapse on its core resulting in a violent Supernova Explosion.

Given the size of a Star, a Star about 3 times bigger than our Sun will transform into a Neutron Star while Star even more massive will transform into a Black hole. A dense region from which even light cannot escape.