PCS 181 Lecture Notes - Lecture 3: Active Galactic Nucleus, Giant Star, Radiography
23 Apr 2016
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Document Summary
A collapsed stellar core is 25 mo. determine radius of its event horizon (=radius of black hole) Several constants in previous equation: 2, g, mo, vesc (=c) Collapsed stellar core is 25 mo. determine radius of its event horizon (=radius of black hole) Thus if mass of singularity is given in solar masses, ex: 9 mo, 20 mo, 27 mo. Then rs is, respectively, 27 km, 60 km, 81 km. Generally divided into 4 categories depending on mass. Mini black hole (=primordial bh): hawking postulates they might have formed during. Big bang but never found: rs 9x10-6 km, rs 9x10-3 m, rs 9mm, mass mass of earth. Stellar black hole: forms from gravitational collapse of a single star of large mass: mass 3 mo to 100 mo, rs 9 km to 300 km. They emit no light, so we can"t see a black hole directly.
