Observations of the Polar ST Leonis Minoris during an Extreme Low State: Identification of the Secondary Star

We present near-infrared (1.85-2.47 μm) and optical (4300-5800 Å) spectroscopic observations of the polar ST Leonis Minoris (ST LMi) in an extreme low state. The near-infrared spectrum, showing no emission lines whatsoever, is produced solely by the secondary star. We have fitted the spectrum with a series of stellar atmosphere models and found the secondary star to have a temperature of 2800+/-200 K. Six months later, ST LMi was reobserved in the near-infrared, at which time mass transfer had resumed, and the system was in a high state.