Var., period. and contact binaries in WISE

We present an analysis of an all-sky sample of ~450 000 AllWISE+NEOWISE infrared light curves of likely variables identified in AllWISE. By computing periodograms of all these sources, we identify ~56 000 periodic variables.

Of these, ~42 000 are short-period (P < 1 d), near-contact, or contact eclipsing binaries, many of which are on the main sequence. We use the periodic and aperiodic variables to test computationally inexpensive methods of periodic variable classification and identification, utilizing various measures of the probability distribution function of fluxes and of time-scales of variability. The combination of variability measures from our periodogram and non-parametric analyses with infrared colours from WISE and absolute magnitudes, colours, and variability amplitude from Gaia is useful for the identification and classification of periodic variables.