TITLE: GCN CIRCULAR NUMBER: 352 SUBJECT: GRB 990506 - Optical Observations DATE: 99/06/16 16:03:20 GMT FROM: Holger Pedersen at Copenhagen U Obs H. Pedersen, J. Hjorth, B. L. Jensen (Copenhagen), A. O. Jaunsen (Oslo), and S. Holland (Aarhus) report on behalf of a larger collaboration: "We have re-inspected our optical (R-band) images of GRB 990506 (GCN #342) obtained on 6.96 May 1999 and 7.91 May 1999 UT. We find no convincing evidence for any stellar or extended object at the position of the proposed radio transient (GCN #350), neither in the sum image, nor in subsets. For the first night, we estimate a limiting magnitude of R > 23.5 (for point sources). Our images are available upon request."