Mapping the Milky Way: Stars

• Global optical view: Tycho-2 map of brightest 2.5M(!) stars in B and V
• Truly global view: near infrared
• Stellar disk (Population I): thin, thick
• Spheroid (Population II): stellar halo, bulge
• cartoon of Milky Way structure

A Census of Local Stars

• the 151 (apparently) brightest stars
• RECONS data on the 100 nearest stars
• biases in star surveys
• the present-day luminosity function

Newtonian Gravitation

• inverse square law
• equivalence principle
• gravitational field
• superposition

Gauss' Law for Gravitation

• electrostatics vs Newtonian gravitation
• a blast from the past: Gauss's Law covered in Lecture 3 and Lecture 4 of PHYS 212
• bait and switch: importing Gauss to gravity