TITLE: GCN GRB OBSERVATION REPORT NUMBER: 399 SUBJECT: GRB 990806 Optical observations DATE: 99/08/10 00:24:42 GMT FROM: Fiona Harrison at CalTech J. Prochaska, I. Thompson (OCIW), J. S. Bloom, F. A. Harrison, S. R. Kulkarni (CIT), D. A. Frail (NRAO) report: "On the night of 7 August 1999 UT, we imaged the field of GRB 990806 (Piro GCN #392; Gandolfi GCN #393) with the Swope 40-inch telescope at Las Campanas Observatory. The total integration time was 900-s in R (approximately Cousins) and the mean epoch was 7.4186 August 1999 UT. Photometric comparison with secondary standards from Kemp et al. (GCN #395) yields a 3-sigma point source detection threshold of R~=22.5. In agreement with previously reported measurements (GCN #394; GCN #395; GCN #396; GCN #397; GCN #398), we find no new sources not present in the Digital Sky Survey. A 4'x4' image of the field centered on the BeppoSAX position can be obtained at http://www.srl.caltech.edu/~fiona/grb990806.html The reduced, medianed frame can be obtained at http://www.srl.caltech.edu/~fiona/grb990806-aug7-lco-rband-900s.fits This message can be cited."