TITLE: GCN CIRCULAR NUMBER: 9870 SUBJECT: GRB 090902B: Optical afterglow candidate DATE: 09/09/03 05:30:08 GMT FROM: Daniel Perley at U.C. Berkeley D. A. Perley, I. K. W. Kleiser, and J. M. Rex (UC Berkeley) report: We imaged the location of the Swift-XRT candidate afterglow (GCN 9868, Kennea et al.) of extremely bright Fermi GRB 090902B (GCN 9866, Bissaldi et al.) with the Nickel 1-meter telescope at Lick Observatory. We marginally detect a faint source in individual 600-second exposures at the western edge of the XRT error circle with a magnitude comparable to the Digitized Sky Survey limit. This is likely the same source observed by the UVOT (GCN 9868, Swenson et al.). We cannot confirm fading behavior at this time, and further observations are encouraged. A finding chart showing the XRT error circle and the putative afterglow is available at the following URL: http://lyra.berkeley.edu/~dperley/090902b/090902b_lick.jpg