AN Ursae Majoris

J. P. Osborne, EXOSAT Observatory, reports that on Mar. 31.4 UT this AM-Her object was fortuitously seen by the low-energy telescope during an observation of a nearby object. An uneven, double- peaked lightcurve is clearly visible. AN UMa has been observed to have three different optical states (Liebert et al. 1982, Ap.J. 254, 232), with a factor 40 difference in the soft x-ray flux between the bright and intermediate states. The count rate seen by EXOSAT strongly suggests that the object has now returned to its bright state (mag 14.0-14.5), which has not been observed since 1977 Jan. Spectroscopic and photometric observations are urged.