GCN Circular 9960
Z. Cano, A. Melandri, C. Mundell, D. Bersier, R.J. Smith, I. A. Steele, S. Kobayashi, C.J. Mottram (Liverpool JMU), A. Gomboc (U. Ljubljana) report, on behalf of the Liverpool GRB group: The Faulkes Telescope South (Australia) observed the field of GRB 090927 (Swift trigger=370846, Grupe et al., GCN 9945) on 2009 September 27 and 28. The afterglow candidate reported by Gronwell & Grupe (GCN 9946) is clearly visible and fading at position: RA(J2000): 22 55 53.42 Dec(J2000): -70 58 49.54 with the following magnitudes calibrated wrt USNO-B1 objects in the field: I = 19.4 +/- 0.1 @ 3.66 hrs I = 21.3 +/- 0.2 @ 27.23 hrs R = 19.9 +/- 0.1 @ 4.21 hrs Observations are on-going, but we derive preliminary decay rates using the above FTS measurements and the R-band magnitude reported by Levan et al. (GCN 9958) to be: alpha_I=0.9+/-0.2, alpha_R=1.2+/-0.2.