TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5557 SUBJECT: GRB060906: Danish/DFOSC optical observations DATE: 06/09/10 23:53:09 GMT FROM: Klaas Wiersema at GRACE/U of Amsterdam K. Wiersema (University of Amsterdam) and E. Rol (University of Leicester) report: We observed the position of GRB060906 (Racusin et al. GCN5528) with the Danish 1.5m telescope at La Silla equipped with DFOSC. Observations were done under high airmass, starting on September 8 08:06 UT and ending at 08:52 UT. In the sum of 7 x 5 min exposures in I band we do not detect the optical afterglow (Cenko et al. GCN5529). Using a sample of 23 USNO-B stars we find a 3 sigma upper limit of I = 21.95. The standard deviation in the zeropoint as determined from the USNO stars is 0.24 mag.