Absolute visual magnitudes

Absolute visual magnitudes for stars are derived from their spectral type and luminosity class. Calibrations are stored in files spec_par.V, spec_MV.IV, spec_par.III, spec_MV.II, spec_MV.Ia, spec_MV.Iab, spec_MV.Ib in oyster/starbase.

amv_stars Compute MV for all stars in startable.
amv_star(spectrum$<$_char$>$)

Function. Return MV for star with specified spectrum.