TITLE: GCN CIRCULAR NUMBER: 8503 SUBJECT: GRB 081109A optical upper limit DATE: 08/11/09 14:15:04 GMT FROM: AAVSO GRB Network at AAVSO Peter Nelson (Ellinbank, Victoria, Australia) reports to the AAVSO International High Energy Network the following optical observation of GRB081109A (GCN #8500 Immler et al.; GCN #8501 D'Avanzo et al.): Peter Nelson has obtained a limiting magnitude on the optical afterglow of GRB081109A (Immler et al., GCN #8500). The near IR afterglow position RA: 22:03:09.72 Dec: -54:42:39.5 found by D'Avanzo et al. (GCN #8501) was observed for 120 seconds using a 0.32-meter Newtonian with an SBIG ST8XE CCD and an R filter under poor photometric conditions. The mid-point of the observations was 2008 Nov 09.5188 UT, approximately 5.4 hours after the burst. The afterglow was not detected to an upper limit of R=18.1, using the USNO-A2.0 star 0300-37476396 (R=13.2) as the comparison. A detailed report of these observations is available on the AAVSO website at ftp://ftp.aavso.org/grb/PeterNelson_081109_2454780.06997_.txt A fits image is available at ftp://ftp.aavso.org/grb/PeterNelson_081109_2454780.06997_.fits The AAVSO thanks the Curry Foundation for their continued support of the AAVSO International High Energy Network.