IUE monitoring of WR140 (WC7+O4-5)

Abstract

We present the first results of the IUE monitoring campaign of the WC7+O4-5 binary system WR140. Thirty-four high-resolution short-wavelength spectra were obtained in 1979—93, i.e., over more than one orbital period of 7.9 yr. The spectra show variations in the strong resonance lines of CIV and SiIV: large variations occur at the blue edges of the absorption parts of their P-Cygni profiles just after periastron passage. The observed profile changes are discussed in terms of a velocity variation at periastron passage and/or turbulence in the sightline to the O4—5 star at this time.