Near-infrared variability in the 2MASS calibration fields: A search for planetary transit candidates

The Two Micron All Sky Survey (2MASS) photometric calibration observations cover similar to 6 square degrees on the sky in 35 calibration fields,'' each sampled in nominal photometric conditions between 562 and 3692 times during the 4 years of the 2MASS mission. We compile a catalog of variables from the calibration observations to search for M dwarfs transited by extrasolar planets. We present our methods for measuring periodic and nonperiodic flux variability. From 7554 sources with apparent K-s magnitudes between 5.6 and 16.1, we identify 247 variables, including extragalactic variables and 23 periodic variables. We have discovered three M dwarf eclipsing systems, including two candidates for transiting extrasolar planets.