ASTR-1010 Lecture Notes - Lecture 23: Galaxy Rotation Curve, Orbital Period
5 Apr 2017
School
Department
Course
Professor
Document Summary
Stars continuously form in disk as the galaxy grows older. Blue color is due to scattering of light by interstellar dust grains and the red color arises from hydrogen emission. Not common in the milky way"s halo. There are no young, hot stars to create them (they are actually concentrated in the spiral arms of the disk) In the disk: in the same direction, in the same plane, bobble up and down. In halo/ bubble: in different directions, at various angles to the disk, have higher velocities. Total mass of the milky way is 1012 m (dot) Total number of stars in it: 2 x 1011. Sun"s orbital period in it: 230 million years. Sun"s distance from the center: 28,000 light years. **in the milky way, there is about 80% more mass than we can see dark matter.
