PCS 181 Lecture Notes - Lecture 11: Giant Star

• School: Ryerson University
• Department: Physics
• Course: PCS 181
• Professor: Margaret Buckby

Document Summary

They emit no light, so we can"t see a black hole directly. We seek a stellar black hole in a binary system consisting of a visible giant star and an invisible and an invisible companion. (=bh candidate). We seek a giant star that wobbles in its orbit. The companion causing the wobble must be invisible. The invisible companion must have a mass >~3mo. The system must be emitting x-rays (from a surrounding accretion disk). We can see a visible supergiant star of ~30mo. The supergiant star is wobbling under the influence of an invisible companion. Mass of the invisible companion is ~9. 5mo. Recall that a black hole singularity has a mass >~3mo. A black hole accretion disk has a luminosity of 1030 w and emits x-rays of wavelength. Determine its temperature (in k) and its radius (in km). L = 4 (3. 14) r2 (sigma) t4.