TITLE: GCN CIRCULAR NUMBER: 6480 SUBJECT: GRB 070531: NOT nIR observations DATE: 07/05/31 15:09:03 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo, A.J. Castro-Tirado (IAA-CSIC, Granada), C. Gonzalez (IAC Tenerife), A. Cabrera (GTC Project Office) on behalf of a larger collaboration, report: "We have observed the field of GRB 070531 (Markwardt et al., GCNC 6475) in J, H and K-bands using the 2.5mNOT (+NOTCAM) Roque de los Muchachos Observatory (Spain) starting at 04:17 UT (2.11 hours after the burst). We do not detect any source in the XRT error box (Page et al. GCNC 6477) down to J~19.5 (3-sigma)." This message can be quoted