TITLE: GCN CIRCULAR NUMBER: 11265 SUBJECT: GRB 100909A: Faulkes Telescope North afterglow candidate DATE: 10/09/09 14:58:36 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), Z. Cano, D. Bersier (LJMU), P. O'Brien (U. Leicester) report on behalf of a large collaboration: The Faulkes Telescope North automatically began observing INTEGRAL GRB 100909A (Mereghetti et al. GCN Circ. 11260) on September 09, 10:42:34 UT, 1.6 hours from the GRB trigger time. Within the Swift-XRT error circle (Siegel et al. GCN Circ. 11261) we identify an uncatalogued, possibly fading object at the following position: RA(J2000.0): 04:55:47.86 Dec(J2000.0): +54:39:32.1 with the following magnitudes: Mid Time from Exposure Filter Magnitude GRB (hours) (s) ------------------------------------------------------- 2.07 540 R 21.6 +- 0.2 2.16 520 i 20.6 +- 0.1 5.05 1200 R 22.1 +- 0.2 ------------------------------------------------------- Calibration was done against the nearby USNOB-1 star RA,DEC=04:55:49.14, +54:39:42.66, assuming R2=16.82, I=16.06. We note that the uncatalogued source lies 3" from a USNOB-1 object with R2=18.54.