AST222H1 Lecture Notes - Lecture 30: Palomar Transient Factory, Peculiar Velocity, Parsec

• School: UTSG
• Department: Astronomy and Astrophysics
• Course: AST222H1
• Professor: Jo Bovy

Document Summary

A cepheid from m31 shows a nebula therefore andromeda is a proper galaxy (in 1925) Found strong relationship with distance and velocity (in early 1930s) Hubble"s constant times distance, velocity (km/s), distance (mpc) The best measurement we have right now is 73km/s/mpc. A bit of error, usually possible for it to be a few kilometers outside 73, more or less (own notes) Once you know this correlation is there, can measure a galaxy"s velocity and distance. Want to get distances so you can study this law. In a few years there is a survey starting to look at southern part of the sky and map it. Form the use of this survey, we"ll soon get more supernovae. Hubble"s law is terrific new for distance measurements. Can measure recession velocity with accuracy and ease. Galaxy redshift surveys: survey an area of the sky, identify each galaxy and look for its redshift (mainly focused on measuring redshifts, doppler shifts towards longer wavelengths)