TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1993 SUBJECT: GRB 030328 Optical Observations DATE: 03/03/29 17:03:41 GMT FROM: Jens Hjorth at U.Copenhagen M. I. Andersen (Astrophysikalisches Institut Potsdam), G. Masi (University of Rome "Tor Vergata" and ESO, Chile), B. L. Jensen and J. Hjorth (University of Copenhagen) report: We have obtained R-band observations of the optical afterglow of GRB 030328 (Peterson & Price, GCN 1974), using the Danish 1.54m telescope (La Silla) + DFOSC. Using the zero point reported by Fugazza et al. (GCN 1982) (R = 16.31 for star B) a preliminary analysis gives Mar. 29, 02:59 UT 20.91 +/- 0.09 Mar. 29, 03:12 UT 20.73 +/- 0.07 Mar. 29, 03:34 UT 21.00 +/- 0.09 Mar. 29, 03:54 UT 20.85 +/- 0.06 Mar. 29, 04:15 UT 21.00 +/- 0.07 Mar. 29, 04:42 UT 20.95 +/- 0.07 Mar. 29, 05:21 UT 21.10 +/- 0.07 Mar. 29, 05:53 UT 21.03 +/- 0.07 Mar. 29, 07:17 UT 21.23 +/- 0.10 Mar. 29, 07:46 UT 21.36 +/- 0.11 A fit to this data set gives a decay index of alpha = 1.6 +/- 0.3. If the two last data points are ignored and the two data points of Fugazza et al. are included, a decay index of alpha = 1.2 +/- 0.2 is derived, consistent with the early decay index of alpha = 1.0 +/- 0.1 reported by Price & Peterson (GCN 1977). This may indicate that the light curve steepened around t = 0.8 days.