TITLE: GCN CIRCULAR NUMBER: 10142 SUBJECT: GRB 091109: Faulkes Telescope South observations DATE: 09/11/09 12:12:49 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), R.J. Smith, C.G. Mundell, D. Bersier, A. Melandri, Z. Cano, S. Kobayashi, C.J. Mottram, I.A. Steele (Liverpool JMU), A. Gomboc (U. Ljubljana) report on behalf of a large collaboration: On 2009 November 9 at 09:26:10 UT the 2-m Faulkes Telescope South began observing GRB 091109 (Oates et al., GCN Circ. 10138) using the R and i' filters. We detect the UVOT optical afterglow candidate at a position consistent with that reported by Oates et al. (but not consistent with the object reported by REM Antonelli et al., GCN Circ. 10139), with the following magnitudes: Mid Time from GRB Total Exp Filter Magnitude (hours) (s) ----------------------------------------------------- 4.74 600 i' 21.7 +- 0.3 5.29 600 R 21.95 +- 0.25 ----------------------------------------------------- Magnitudes have been calibrated from the nearby USNOB-1 star 20:37:02.508, -44:09:33.68, using R2=17.52 and I=17.61.