TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2259 SUBJECT: GRB 030329/SN 2003dh: Jitter Episode DATE: 03/05/29 20:36:24 GMT FROM: Krzysztof Z. Stanek at CfA K. Z. Stanek, D. Bersier, M. Calkins, D. L. Freedman and T. Spahr (Harvard-Smithsonian CfA) report: We continued imaging of the SN 2003dh (Matheson et al. GCN 2107, 2120; Garnavich et al. IAUC 8108, 8114; Stanek et al. astro-ph/0304173) associated with the GRB 030329 with the FLWO 1.2-m telescope between May 26 UT 05:00 and May 29 UT 05:00 (57.7 and 60.7 days after the burst) using standard R_c filter. The increase in brightness by >0.3 mag observed by Stanek et al. (GCN 2244) between May 21 and May 23 UT was followed by a decay of ~0.3 mag and then by an increased scatter in the light curve: UT R dR Filter Texp ---------------------------------------------------- 2003-05-26 05:00 21.612 0.06 R 5x900 sec 2003-05-28 04:50 21.456 0.07 R 4x900 sec 2003-05-29 05:00 21.617 0.09 R 4x900 sec The figure showing the light curve since May 20 UT can be accessed at: http://cfa-www.harvard.edu/~kstanek/jitter.jpg We should stress that we have a very extensive data set for this object obtained with exactly the same instrumentation and this "jitter episode" is very unusual when compared to the whole data set and we strongly believe that it is real and it might continue. Therefore, observations using larger telescopes, also in other bands, are strongly encouraged. Any use of these data should include proper reference to this GCN.