Since the light from galaxies represents the integrated contribution of its consitutient stars, then we can learn about stellar populations in galaxies by modelling their light by summing up individual stellar spectra for different kinds of stars. ... The data cover the wavelength range 3500 - 9000 angstroms. ... Retrieve Digital Stellar Spectra Click on the appropriate spectral type. ... Note that the designation V means main sequence, IV means subgiants, III means giants, I means supergiant. ...