Chandrasekhar limit

The Chandrasekhar limit (named after Subrahmanyan Chandrasekhar) is the maximum nonrotating mass which can be supported against gravitational collapse by electron degeneracy pressure. It is commonly given as being about 1.4 solar masses. Computed values for the limit will vary depending on the nuclear composition of the mass and the approximations used. Chandrasekhar, eq. (36),, eq. (58),, eq. (43) gives a value of Here, μe is the average molecular weight per electron, is the mass of the hydrogen atom, and is a constant connected with the solution to the Lane-Emden equation. Numerically, this value is approximately (2/μe)2 · 2.85 · 1030 kg, or , where is the standard solar mass. As is the Planck mass, , the limit is of the order of MPl3/mH2.
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. The mass limit at which the force of gravity overcomes the pressure produced by electron degenerate matter. At this mass limit, which corresponds to 1.4 times the mass of the Sun, the electrons are forced inside the atomic nucleus, where they combine with the protons to form neutrons. The gravitational collapse is then halted by the pressure exerted by the neutrons, since they are in a state of matter known as baryon degenerate matter. This pressure is then sufficient to halt further collapse unless the body contains more than three times the mass of the Sun. See also Oppenheimer-Volkoff limit .