{
  "bibcode": "2003GCN..2115....1Z",
  "body": "A. Zeh, S. Klose (Thueringer Landessternwarte Tautenburg),\nA. Henden (USRA/USNO) on behalf of the USNO GRB team and the FUN\n   collaboration, and\nJ. Greiner (MPE Garching),\n\nreport:\n\n\nStimulated by the recent claim of an appearing supernova (SN) component\n(Matheson et al. 2107; Bersier et al., GCN 2109) we have extended our\nnumerical model (Zeh et al., GCN 2081) by the inclusion of a parameter\nwhich describes a delay, dt, between the onset of the SN and the\nGRB and have reanalyzed the USNO data on GRB 030329.\n\nThe long-term evolution in the B-V, B-Rc, and V-Rc color of the\noptical transient (OT) seen in the high-precision USNO data so far can\nindeed be fitted very well with dt approximately 1..2 weeks prior to\nthe burst, although we cannot reproduce the temporary reddening of the\noptical transient which was observed on t=8 days after the burst\n(Henden et al., GCN 2110). On day 9 this temporary reddening of the\nOT has disappeared. It is well possible that this phenomenon was\nrelated to another episode of flattening of the OTs light curve.\n\nFor the sake of clarity we note that the unknown diversity of GRB-SNe\ndoes not allow us to state with certainty that a dt < 0 in our model\ndoes indeed represent a 'SN-first--GRB-later' scenario. So far, this\nparameter simply improves the numerical fit if SN 1998bw is used as a\ntemplate. Its physical reality remains to be clarified.",
  "circularId": 2115,
  "createdOn": 1049741169000,
  "email": "klose@tls-tautenburg.de",
  "subject": "GRB 030329, color evolution",
  "submitter": "Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>",
  "eventId": "GRB 030329"
}