DETECTION OF CYCLOTRON EMISSION FEATURES IN THE INFRARED-SPECTRUM OF ST LMI

We present near-infrared spectroscopic observations of the AM Herculis system ST LMi over the wavelength range 1.0-2.5 mum. During the brigh t phase of the binary cycle, broad and resolvable cyclotron emission h armonics are visible near 1.42, 1.65 and 2.0 mum. We have interpreted the features in terms of an arc-shaped cyclotron emission region consi sting of a high-density, high-temperature spot with an extended leadin g edge of cooler and lower density material. The accretion arc is loca ted close to the weaker pole of magnetic field strength almost-equal-t o 12 MG.