AST201H1 Lecture Notes - Lecture 1: Milky Way, Vera Rubin, Orion Nebula

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST201H1
• Professor: Michael Reid

Document Summary

Galaxy a collection of stars which orbit around one central star. Based on distance from earth (farthest to nearest): star on far side of andromeda. Galaxy > star on near side of andromeda galaxy > star on far side of milky way. Galaxy > star near center of milky way galaxy > orion nebula > alpha centauri > Measures the moving speed of galaxies, and then using the speed to estimate the mass and total light produced by the galaxies. His missing mass idea was not accepted by his contemporaries. Measures how individual stars move around in one galaxy; looks at several galaxies. Discovers that stars nearing the central star move faster than the outer ones, which is the opposite of the gravity law of physics => refer to slide 15. Dark matter: thought to make up 10% of the actual universe. Made of 4. 9% ordinary matter -actual universe, 26. 8% dark matter, and 68. 3%