Temperatures of stars are derived from their spectral type and luminosity class.
Calibrations are stored in files
spec_par.V, spec_par.IV, spec_par.III, spec_par.II, spec_par.I
in oyster/starbase.
teff_stars Compute effective temperature
for all stars in startable.
teff_star(spectrum_char)
Function. Return effective temperature for star with specified spectrum.