IUE observations of gas stream effects in the ultraviolet spectrum of U Cephei.
Kondo, Y.; McCluskey, G. E.; Stencel, R. E.
Abstract
The eclipsing binary U Cephei has been observed with the International Ultraviolet Explorer (IUE) satellite. Nine high-resolution spectra in the mid-ultraviolet (1900-3200 A) and one high-resolution spectrum in the far-ultraviolet (1200-1900 A) were obtained. The effects of gas streaming are clearly seen in the mid-ultraviolet resonance lines of Fe II (2599 A) and Mg II (2795 and 2802 A). The data indicate that much of the gas leaving the G star circles behind the B star and leaves the system. It is suggested that g-mode oscillations in the G star supply part of the energy required to drive the gas out of the system.