SW Sextantis in an excited, low state

Abstract

We present low-resolution spectrophotometric optical observations of the eclipsing nova-like cataclysmic variable SW Sex, the prototype of the SW Sex stars. We observed the system when it was in an unusual low state. The spectrum is characterized by the presence of strong He II and C IV emission lines as well as the normal single peaked Balmer emission lines. The radial temperature profile of the disk follows the expected T ~R^3/4 only in the outer parts and flattens off inside 0.5 times the white dwarf Roche lobe radius. The single peaked emission lines originate in a region above the plane of the disk, at the position of the hot spot.