Interpretation of the UV spectrum of some stars with little reddening

The UV spectrum of a few reddened stars will be decomposed into two terms. One is the direct starlight, F(star,lambda)(0)e(-tau lambda), which is the product of the flux of the star corrected for interstellar extinction, F-star,lambda(0), and of the extinction e(-tau lambda). The second is starlight scattered by interstellar dust into the beam of the observation. This excess of scattered starlight affects the FUV part of the spectrum (lambda < 2200 Angstrom). The combination of both terms gives the shape of the UV spectrum of a reddened star, with its characteristic depression at 2200 Angstrom. (C) 2000 Elsevier Science B.V. All rights reserved.