ASTRO 001H Study Guide - Midterm Guide: Main Sequence, Low Mass, Blueshift
Document Summary
Gravitational equilibrium is when the pressure and gravity are in balance. Gravitational equilibrium is important because that"s when a star begins its life in the main sequence. Hr diagrams: luminosity is y-axis and temperature is x-axis. It"s most prominent feature is the main sequence. Low mass stars are at the bottom of the main sequence, high mass are at the top. More massive stars have shorter lifetimes because they burn out faster. Different masses of stars have different colors because they are different temperatures. High mass stars appear blue, and low mass stars appear red. Older star clusters will be less luminous and towards the bottom of the hr diagram. The two types of star clusters are open and globular. Open star clusters are loosely bound, young and small. Globular star clusters are tightly bound, old, big. Both star clusters have stars that are all the same age and distance from earth.