TITLE: GCN CIRCULAR NUMBER: 9753 SUBJECT: GRB 090807: Liverpool Telescope observations DATE: 09/08/08 11:31:45 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), A. Gomboc (U. Ljubljana), R.J. Smith, C.G. Mundell, I.A. Steele, A. Melandri, S. Kobayashi, C.J. Mottram, D.F. Bersier, Z. Cano (Liverpool JMU), N.R. Tanvir, P. O'Brien (U. Leicester) report on behalf of a large collaboration: On 2009 August 07 at 23:45:24 UT we observed the Swift GRB 090807 (Cannizzo et al., GCN Circ. 9746) with the 2-m Liverpool Telescope. Observations started 8.75 hours after the BAT trigger time and were performed using the r' and i' filters. We could not find any uncatalogued object inside the UVOT-enhanced XRT error circle (Beardmore et al. GCN Circ. 9748) down to the following limiting magnitudes: Time Interval Total Exp Filter Limit (hours from GRB) (s) (mag) ---------------------------------------------- 8.75-9.27 6x300 R > 22.1 9.29-9.90 6x300 I > 22.0 ---------------------------------------------- Magnitudes have been calibrated against the nearby USNOB-1 star RA=18:15:00.349, Dec=+10:15:45.21, using R2=16.19, I=15.82. We note the presence of an uncatalogued source lying outside the XRT error circle at 4.2" from the XRT centroid, at RA=18:14:58.24, Dec=+10:15:58.4 with estimated magnitudes R=22.4 +/- 0.2, I=21.6 +/- 0.2: http://www.fe.infn.it/u/guidorzi/090807_LT_ri.png At the moment we cannot assess whether this source is fading.