2004/12/01 | 埃丁顿光度[Eddington Luminosity]
类别(Ω〖物理〗) | 评论(0) | 阅读(105) | 发表于 13:25
The luminosity a body would have to have for the force generated by radiation pressure to exceed the gravitational force.The force due to radiation pressure is given by
(1)

where L is the luminosity, is the Thomson cross section,r is the radius, and c is the speed of light, and the gravitational force is
(2)

where G is the gravitational constant, M is the mass of the body, and m is the mass of a particle. Equating (2) and (1) gives
(3)

Since experimentally,
(4)

where is the luminosity of the sun and is the sun's mass, a star will be unstable if
(5)

Using a 1/2 power instead,
(6)

Plugging in
(7)

(8)

(9)

(10)

(11)

(12)

gives
(13)

where m has been taken as the mass of a hydrogen atom.
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