GCN Circular 5604
Stefano Covino (INAF/OABr), Daniele Malesani (SISSA/ISAS), and Gianpiero Tagliaferri (INAF/OABr), report on behalf of the MISTICI collaboration: We imaged the field of GRB 060923C (Stamatikos et al., GCN 5591) on 2006 Sep 24 from 3:39 to 4:16 UT with the ESO VLT+ISAAC in the J band under good seeing conditions. Within the refined XRT error circle (Perri et al., GCN 5601) we detect three sources with the following positions (RA, DEC, J2000) and magnitudes: A: 23:04:28.40, +03:55:29.1 19.23 +- 0.03 B: 23:04:28.31, +03:55:29.0 22.87 +- 0.12 C: 23:04:28.18, +03:55:28.5 21.33 +- 0.07 Source C could be extended. Absolute magnitudes are calibrated with respect to two 2MASS stars in the field. The reported errors are only statistical; the absolute calibration error may be of the order of ~0.15 mag. At this stage, we cannot say whether any of these sources is related to GRB 060923C. A finding chart is posted at the followin URL: http://www.sissa.it/~malesani/GRB/060923C/finder_ISAAC.jpg Source A has been reported by Rau et al. (GCN 5598) and could also be marginally visible in the DSS. We acknowledge support from the ESO observing staff at Paranal, in particular Christophe Dumas and Emmanuel Jehin. This message may be cited.