GCN Circular 12992
J. Wren, W. T. Vestrand, P. Wozniak, and H. Davis of Los Alamos National Laboratory report: The RAPTOR wide-field optical monitor located in Maui was observing the location of GRB 120227A which occured at 09:22:46 UT (Fermi GBM trigger 352027367, INTEGRAL SPI-ACS trigger 6478). Our system covered the entire 6.33 degree radius statistical error region specified in the Fermi-GBM Final Position GCN notice. The image that was coincident with the trigger started at 09:22:40.6 UT with an exposure duration of 10 seconds. This unfiltered image has a 3-sigma limiting magnitude of approximately 10.3 when compared to the Tycho-2 V-band. A visual inspection of this image when differenced with one taken 17 minutes later does not show any candidate optical counterparts within the specified error region.