IUE observations of the ultraviolet spectrum of the close binary del Pic.

Abstract

The eclipsing binary δ Pic has been observed with the International Ultraviolet Explorer (IUE) satellite. Two high-resolution spectrograms in the far-ultraviolet (NA1 150-1900) and one high-resolution spectrogram in the mid-ultraviolet of (λλ1900-3200) were obtained. The far-ultraviolet resonance lines of C III (λ1175) and Si IV (λλ1393 and 1402) show the presence of excess absorption due to gas leaving the primary star with velocities as high as 600-700 km s^-1, Many of the interstellar lines are doubled with the two components having mean velocities of -40.6 and +9.0 km s^-1. It is suggested that the negative velocity component may be due to an expanding circumstellar shell surrounding the binary system.