Stellar Property	Observed Quantities	Physics
Temperature	Spectrum - Wavelength of peak of spectrum	Blackbody radiation
	Spectrum - Strength of particular absorption lines	atomic physics
Chemical Composition	spectrum - Presence of particular absorption lines	atomic physics
Distance (direct)	Parallax Angle (Change in apparent	geometry
	angular position 6 months apart
Radial Velocity	redshift or blueshift of spectral lines	Doppler Shift
Transverse Velocity	Proper motion (apparent change
	(over time) in position on the sky)	geometry
	+ distance (somehow!)
Luminosity	apparent brightness	Inverse Square Law
	+ distance (somehow!)
Mass	period + size of orbit of a binary star (*)	Gravity
Radius	velocity of stars in	Doppler shift
	spectroscopic eclipsing binary
	+ length of eclipse	distance = velocity x time
Radius	temperature	Blackbody radiation
	+ luminosity
Distance (indirect)	luminosity from Temperature and Luminosity Class	calibrated HR diagram
	+ apparent brightness	Inverse square law
(*) Size of Orbit for ``visual binary"	angular size	geometry
	+ distance
(*) Size of Orbit for
``eclipsing spectroscopic binary"	velocity + period	Doppler Shift & velocity=dist/time