TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5422 SUBJECT: GRB 060807: K- and R-band observations DATE: 06/08/08 01:46:21 GMT FROM: Daniele Malesani at SISSA-ISAS,Trieste,Italy D. Malesani (SISSA) & S. Piranomonte (INAF/Roma) report on behalf of the MISTICI collaboration: We observed the candidate optical counterpart (Fynbo et al., GCN 5420) of GRB 060807 (De Pasquale et al., GCN 5409; Barthelmy et al., GCN 5421). Observations were carried out in the K and R filters, with NTT+SofI and VLT+FORS1, respectively. The mean times were 8.46 and 8.72 hr after the burst. The candidate is well detected in both filters, and shows a very red color. Preliminary calibrations against 2MASS and USNO-B1 (R1 magnitudes) shows R-K ~ 5 (assuming negligible time variations between the two epochs). We warn that there is some scatter (by ~0.2 mag) in the calibration for both the R- and K bands, so this value should be still considered as preliminary. We acknowledge prompt support from the VLT and NTT observing staffs, in particular Claudio Melo and Valentin Ivanov. This message can be cited.