TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1999 SUBJECT: GRB 030329: OT B and R photometry, decline rate DATE: 03/03/29 21:12:43 GMT FROM: Avishay Gal-Yam at Tel Aviv U, Israel A. Gal-Yam, E. O. Ofek, D. Polishook and E.M. Leibowitz (Wise observatory, TAU) report: We are observing the OT of GRB 030329 (Peterson & Price, GCN 1985) using the Wise observatory 1m telescope + SITe CCD camera, starting March 29, 17:15 UT (5.6 hours after the burst). Large number of 300 s B, 120 s V and 120 s R-band frames are being obtained under highly variable conditions, with passing clouds. We detect the OT on numerous B, V and R-band images. A rough calibration using nearby bright USNO A-1 stars gives R~14.3 and B~15 for the OT. We can also estimate the decline rate to be about 0.3 mag/hour in the R-band, from the first two hours of data. Further data acquisition and analysis are underway.