We present high cadence ( 1–10 hr ^ { -1 } ) time-series photometry of the eruptive young variable star V1647 Orionis during its 2003–2004 and 2008–2009 outbursts .
The 2003 light curve was obtained mid-outburst at the phase of steepest luminosity increase of the system , during which time the accretion rate of the system was presumably continuing to increase toward its maximum rate .
The 2009 light curve was obtained after the system luminosity had plateaued , presumably when the rate of accretion had also plateaued .
We detect a ‘ flicker noise ’ signature in the power spectrum of the lightcurves , which may suggest that the stellar magnetosphere continued to interact with the accretion disk during each outburst event .
Only the 2003 power spectrum , however , evinces a significant signal with a period of 0.13 d. While the 0.13 d period can not be attributed to the stellar rotation period , we show that it may plausibly be due to short-lived radial oscillations of the star , possibly caused by the surge in the accretion rate .