ING photometry and spectroscopy of the optical counterpart of the x‐ray transient GRO J0422+32

Abstract

We present new photometric observations of the GRO transient J0422+32 which show a two‐hour and a five‐hour variation of only 0.1 magnitude in amplitude. Spectroscopic observations during the late decline of the August 1992 outburst and during the August 1993 outburst show variability in the double‐peaked Balmer and He ii profiles on a timescale of hours and reveal red‐shifted emission components at two epochs.