Sunday, 15 November 2009

What is Chandrasekhar's Limit?

The mass thats required in a star for it to have so much gravity as to contract the diameter of star on its death, so much, that the centrifugal force which throws out matter is less than it. Result is continuous contraction resulting in less and less diameter and so more and more gravity, due to more mass pressed in a smaller area. This goes on to an unlimited extent so that ultimately diameter goes on decreasing and gravity increasing so much as not to let even light out of the star. A black hole results. That mass limit is 1.44 times the mass of our SUN. Below that, there will not be so much gravity generated and the star cannot become a black hole... miniscule body. It remains a big colder dwarf dead star, white dwarf etc. with normal gravity.(far smaller diameter than the original burning star... due to burning up, throwing and blasting off most of the matter in the life and end stages drama) We can see it.
Cahndrashekhar was a scientist from India who worked, theorised, calculated and showed this mass limit. Below this limit, a star wil be a dead star normal. A mass above this limit will become a black hole.
It is called the Chandrashekhar's limit.
The evidenceof such bodies can be known only thru gamma rays from it, its gravity influence around it, photos of matter pulled by a black hole from other bodies etc. It can't be seen in visible spectrum.



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