AST201H1 Lecture Notes - Lecture 11: Luminosity Distance, Solar Mass, Absorption Spectroscopy

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Macdonald

Document Summary

Ast201 lecture 11: hr diagram and main sequence. Properties of stars: temperature - colour composition - spectral lines distance - parallax. Luminosity - distance + brightness: surface temperature vs luminosity. H-r diagram: oh be a fine gorilla kiss me, hottest > coolest. Luminosity - brighter at top, dimmer at bottom. Fusion in the cores of main sequence stars: protons join (fuse) to form helium and energy this only happens if there is tremendous temperature and pressure like in the cores of main sequence stars. We use solar masses or msun to state the masses of stars. 1 msun means: same mass as the sun. 10 msun means: 10x the mass of the sun. 0. 1 msun means: 1/10 the mass of the sun. Most of stars in universe are less massive than sun. February 11, 2020: universe is full of low mass stars and sun is average mass.