Infrared spectroscopy of the supersoft X-ray source MR Vel

We describe the infrared spectrum of the galactic supersoft X-ray source MR Vel (RX J0925.7-4758) in the wave- length range of 1.1−2.6 µm. We find Paschen, Brackett, He I, He II and neutral and ionized oxygen lines in emission. No traces of the secondary star were found. P-Cygni profiles were observed in Paschen β and Brackett γ, from which we conclude that these lines arise in a wind. Fitting the optical and infrared energy distribution with a supercritical disk model, incorporating white dwarf and secondary star contributions, we were able to constrain the distance to 2−5 kpc, which implies an absolute magnitude MV between −2 and 0.