TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2273 SUBJECT: GRB 030528: Optical Observations DATE: 03/06/06 17:36:24 GMT FROM: Nestor Mirabal at Columbia U. N. Mirabal & J. P. Halpern (Columbia U.) report on behalf of the MDM Observatory GRB follow-up team: "We obtained I-band images on the MDM 1.3m for 1.5 hours on June 5.28, covering the positions of most of the Chandra X-ray sources listed by Butler et al. (GCN 2269). We detect optical counterparts of three of the four sources within the revised SXC region reported by Villasenor et al. (GCN 2261). The source CXOU J170400.3-223710, tentatively proposed as the GRB afterglow by Greiner et al. (GCN 2271), is not detected in any of our images to a preliminary limiting magnitude I > 21.5. Comparison with prior observations and deeper optical images of this location would be useful." This message may be cited.