TITLE: GCN CIRCULAR NUMBER: 6476 SUBJECT: GRB 070531: Liverpool Telescope Optical Observations DATE: 07/05/31 03:55:08 GMT FROM: Andreja Gomboc at LT,ARI,Liverpool JMU A. Gomboc (Univ. of Ljubljana), R.J. Smith, C.G. Mundell, A. Melandri, I.A. Steele, D. Carter, A. Monfardini, C.J. Mottram, S. Kobayashi, D. Bersier, M. Burgdorf (Liverpool JMU) and C. Guidorzi (Uni-Bicocca/INAF-OAB) report: The 2-m Liverpool Telescope robotically followed up GRB 070531 (Swift trigger 280958, GCN 6475 Markwardt et al.) and started observing the field at 3.7 min after the trigger time with the RINGO polarimeter. Photometric observations started at 11.9 min after the trigger time. In first images we do not detect any new object down to: Filter t_mid (min from GRB) Tot_Exp (s) Lim ------------------------------------------------------------------- r' 13.2 60 18.2 i' 19.0 120 17.9 ------------------------------------------------------------------ Magnitudes were calibrated vs R2 and I mag from the USNOB1 catalogue. Further analysis is ongoing.