2014MNRAS.442L..23M

We report the occurrence of a deep low state in the eclipsing short-period cataclysmic variable (CV) IR Com, lasting more than two years. Spectroscopy obtained in this state shows the system as a detached white dwarf plus low-mass companion, indicating that accretion has practically ceased. The spectral type of the companion derived from the SDSS spectrum is M6-7, somewhat later than expected for the orbital period of IR Com. Its radial velocity amplitude, K2 = 419.6±3.4 km/s, together with the inclination of 75°-90° implies 0.8 < Mwd <1.0 M_☉. We estimate the white dwarf temperature to be ≃ 15 000 K, and the absence of Zeeman splitting in the Balmer lines rules out magnetic fields in excess of ≃ 5 MG. IR Com still defies an unambiguous classification, in particular the occurrence of a deep, long low state is so far unique among short-period CVs that are not strongly magnetic.