Detailed optical studies of the galactic supersoft X-ray source QR and (RXJ0019.8+2156)

We present high-speed long term photometric observations from 1992 to 1996 (UBVRI), as well as recently obtained (1997) spectrophotometric and high re solution spectroscopic studies of the bright galactic supersoft X-ray sourc e RX J0019.8 +2156. Our photometry reveals a highly variable object. The sh ortest observed quasi-periodic variations are humps with a period of approx imate to 1.8 h. The timings of the main minimum are not exactly regular and occur on average around phase phi = 0.0. With our new data set we calculat ed an update of the orbital period. Our simultaneous spectroscopic and spectrophotometric studies from 1997 giv e an even more detailed insight: blue and red shifted satellite lines at He II lambda 4686 and at the strong Balmer lines, which are interpreted as hi gh velocity outflows, can clearly be detected. We also present for the firs t time an analysis of this supersoft source by means of Doppler tomography. The lines of He II (lambda lambda 4542, 4686), H-alpha and H-beta show no emission from an accretion disk. These emission lines originate in regions within the binary system with very low velocities. The spatial origin of th e emitting material is not quite clear and will be investigated in a follow -up paper.