GCN Circular 2115
A. Zeh, S. Klose (Thueringer Landessternwarte Tautenburg), A. Henden (USRA/USNO) on behalf of the USNO GRB team and the FUN collaboration, and J. Greiner (MPE Garching), report: Stimulated by the recent claim of an appearing supernova (SN) component (Matheson et al. 2107; Bersier et al., GCN 2109) we have extended our numerical model (Zeh et al., GCN 2081) by the inclusion of a parameter which describes a delay, dt, between the onset of the SN and the GRB and have reanalyzed the USNO data on GRB 030329. The long-term evolution in the B-V, B-Rc, and V-Rc color of the optical transient (OT) seen in the high-precision USNO data so far can indeed be fitted very well with dt approximately 1..2 weeks prior to the burst, although we cannot reproduce the temporary reddening of the optical transient which was observed on t=8 days after the burst (Henden et al., GCN 2110). On day 9 this temporary reddening of the OT has disappeared. It is well possible that this phenomenon was related to another episode of flattening of the OTs light curve. For the sake of clarity we note that the unknown diversity of GRB-SNe does not allow us to state with certainty that a dt < 0 in our model does indeed represent a 'SN-first--GRB-later' scenario. So far, this parameter simply improves the numerical fit if SN 1998bw is used as a template. Its physical reality remains to be clarified.