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We present the detection of day-timescale periodic variability in the r-bandlightcurve of newly outbursting FU Orionis-type object HBC 722, taken from > 42nights of observation with the CQUEAN instrument on the McDonald Observatory2.1m telescope. The optical/near-IR lightcurve of HBC 722 shows a complex arrayof periodic variability, clustering around 5.8 day (0.044 mag amplitude) and1.28 day (0.016 mag amplitude) periods, after removal of overall baselinevariation. We attribute the unusual number of comparable strength signals to aphenomenon related to the temporary increase in accretion rate associated withFUors. We consider semi-random "flickering", magnetic braking/field compressionand rotational asymmetries in the disk instability region as potential sourcesof variability. Assuming the 5.8 day period is due to stellar rotation and the1.28 day period is indicative of Keplerian rotation at the inner radius of theaccretion disk (at 2 R(star)), we derive a B-field strength of 2.2-2.7 kG,slightly larger than typical T Tauri stars. If instead the 5.8 day signal isfrom a disk asymmetry, the instability region has an outer radius of 5.4R(star), consistent with models of FUor disks. Further exploration of the timedomain in this complicated source and related objects will be key tounderstanding accretion processes.

Variability at the Edge: Optical Near/IR Rapid Cadence Monitoring of Newly Outbursting FU Orionis Object HBC 722