The K-band surface brightness of late-type stars and the distance to cataclysmic variables

The method for determining the distance to cataclysmic variables using the K-band surface brightness is reexamined with a new, larger dataset. The K-band surface brightness of dwarf stars is constant over the range 3.0 less than or equal to V-K less than or equal to 5.0, and declines at larger values of V-K. The behavior of the K-band surface brightness depends on luminosity class. Theoretical models of M dwarf stars are roughly consistent with the observations. This new surface brightness relationship reconciles the different distance determinations for HT Cas.