The photometric and spectroscopic characterization of the V Sagittae star V617 Sagittarii

Photometric and spectroscopic characterization of the V Sge star V617 Sgr ( WR 109) is presented. The orbital period, 0.207 day, is the shortest of its class. The optical light curve presents a double wave with minima and maxi ma of uneven brightness. Strong emission lines of highly ionized species su ch as HeII, NV and OVI dominate the optical spectrum. High and low photomet ric states have been observed and the primary eclipse becomes shallower at eruptions. H alpha emission becomes stronger and broader at high state when compared to low state. The striking similarities to V Sge are discussed. T he photometric and spectroscopic observations suggest that a high and asymm etric rim exists associated with the accretion disk. This star is interpret ed as a X-ray quiet galactic counterpart of the supersoft X-ray binaries se en in the Magellanic Clouds.