The rough limiting magnitude of the K band image can be estimated from the USNO-A1 catalog, which gives Red and Blue magnitudes 14.4 and 15.5 for a star with signal to noise ratio 10 in the combined K band image. More careful processing might improve this limit modestly. Combining these two measurements will yield a limit on the spectral slope of the afterglow. This report is citable. The excerpt is 1024 pixels on a side, for a total field size of 4.4 arcminutes, and is centered on the optical transient.
World coordinate system information is included.
The coordinate system zero point was set using the location of the optical transient, so agreement between our astrometry and that of Odewahn et al should not be over-interpreted. Any scientific use of this data should credit E. Falco, C. Petry, C. Impey, and J. Rhoads, on behalf of the KPNO GRB Followup Team. Further observations may be obtained.