Absorption Spectra of Interstellar Grains - Part Two - Fine Structure of the 2200 Hump

Abstract

The ultraviolet TD-1 and IUE spectra of reddened stars were analyzed in order to check the possibility of some differences in the 2200 hump profile, dependent on the spectral type or luminosity of observed stars. The profiles seem to be clearly affected by stellar parameters supporting our earlier hypotesis that this prominent UV spectral feature is at least in part of circumstellar origin. The presently available sets of data do not allow us to check if some regional changes of the "2200" feature exist also in the Galaxy.