TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5161 SUBJECT: GRB060505: VLT observations of the optical afterglow DATE: 06/05/26 14:27:24 GMT FROM: Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr Christina C. Thoene, Johan P.U. Fynbo, Jesper Sollerman, Brian L. Jensen, Jens Hjorth (Dark Cosmology Centre), Pall Jakobsson (Univ. of Hertfortshire), Sylvio Klose (TLS Tautenburg) report on behalf of a larger collaboration: We observed the OT position of GRB060505 (GCN 5123), with FORS2/VLT on May 23.28. Comparison with our FORS1/VLT images from May 5.41 shows that the source has faded from R=21.3 on May 5.41 to R>23 on May 23.28. At the position of the OT, we detect a bright, star-forming region in the spiral arm of the possible host galaxy 2dFGRS S173Z112 with redshift z=0.089 (GCN 5123). Spectroscopy with VLT/FORS2 confirms that this region is part of the host galaxy. Therefore, it is possible that the source reported in GCN 5123 for images taken on May 12th, might actually be the underlying star-forming region. The observations put a strong limit on the presence of an underlying SN similar to SN 1998bw at redshift 0.089, which we would expect to have a magnitude of R=18.4 at the time of our 2nd observation. Therefore, either there is no associated SN, the SN is about 4 magnitudes fainter than SN 1998bw, it is strongly extinguished, or GRB060505 is not at z=0.089. The strengths of the Balmer lines and the fact that the host galaxy is seen close to face on argue against strong dust extinction. We thank the Paranal staff, in particular Claudio Melo and Rachel Gilmour, for excellent support.