Ultraviolet spectroscopy of LSI +61 303.

Abstract

New IUE low-resolution spectroscopy of the X-ray/radio source LSI+61°303 is presented and discussed, and previously reported data critically reassessed. There is no strong evidence for continuum variability; in particular, eight spectra covering the 1200-1950 Å region show a scatter of only ≡3 per cent. There is some variability in the emission lines, possibly related to the star's shell activitiy. The C IV resonance doublet reveals a stellar wind with a terminal velocity of ≡1400 km s^-1. The data are consistent with a 10 R_sun;, T_eff ≅ 15500K star at 2.3 kpc, reddened by E(B-V) = 0.75.