Observations of the extreme-ultraviolet transient RE J1255+266: A short outburst of a WZ Sge system?

Abstract

We present a previously unpublished ROSAT Wide Field Camera observation of the transient source RE J1255 + 266 made just 4d before the discovery observations. The source is not detected, limiting the duration of the outburst to be less than expected for a superoutburst of a WZ Sge system. We also present a marginal detects of X-ray emission from RE J1255+266 using ASCA. The most probable luminosity is 6 × 1029 erg s-1, which is very similar to WZ Sge itself. We discuss the nature of the source in the light of these observations, and conclude that it is most probably a WZ Sge system, but that the observed outburst must have been a normal dwarf nova outburst.