UGPS J194310+183851: an unusual optical and X-ray faint cataclysmic variable?
Maccarone, T. J.; Cooper, W. J.; Lucas, P. W.; Miller, N.; Guo, Z.; Morris, C.; Drew, J. E.; Strader, J.; Swihart, S. J.; Britt, C. T.
United Kingdom, United States, Italy, Chile
Abstract
The growing number of multi-epoch optical and infrared sky surveys are uncovering unprecedented numbers of new variable stars, of an increasing number of types. The short interval between observations in adjacent near-infrared filters in the UKIDSS Galactic Plane Survey (UGPS) allows for the discovery of variability on the time-scale of minutes. We report on the nature of one such object, through the use of optical spectroscopy, time series photometry, and targeted X-ray observations. We propose that UGPS J194310.32+183851.8 is a magnetic cataclysmic variable star of novel character, probably featuring a longer than average spin period and an orbital period likely to be shorter than the period gap (i.e. Porb < 2 h). We reason that the star is likely a member of the short-period intermediate-polar subclass that exists below this period boundary, but with the additional feature that system's spectral energy distribution is fainter and redder than other members of the group.