What are the observed properties of stars? This lecture is a quick
review of the basic observational properties of stars, introducing
luminosity, spectral classification, the luminosity-radius-temperature
relation, and the Hertzsprung-Russell (H-R) diagram. This sets up the
empirical basis of subsequent lectures on the lives and deaths of stars.
Recorded live on 2009 Nov 9 in Room 1005 Smith Laboratory on the
Columbus campus of The Ohio State University.