{
  "bibcode": "2006GCN..4809....1F",
  "body": "T. A. Fatkhullin, V.V. Vlasyuk, V. V. Sokolov, A. V. Moiseev (SAO-RAS Nizhnij Arkhyz),\nS. Guziy and A. J. Castro-Tirado (IAA-CSIC Granada), on behalf\nof a larger collaboration, report:\n\n\"We have obtained optical spectroscopy of the GRB 060218 optical\ncounterpart (Cusumano et al. GCNC 4775) with the 6.0m BTA telescope\nof SAO-RAS in Zelenchuk, equipped with SCORPIO. First epoch\nspectroscopy in the 3500-7500 A range was obtained on Feb 20.65 UT,\nconfirming z = 0.033 (Mirabal and Halpern GCNC 4792). Second epoch\ndata was gathered on Feb 21.65 UT.  Comparison between the two datasets\nclearly reveals continuum variations that we interpret as the emergence\nof the underlying type-Ic SN spectrum, strengthening the SN-GRB 060218\nrelationship first suggested by Masetti et al. (GCNC 4803).  In\nparticular, an \"emission peak\" at ~4500 A is showing up, possibly as\na result of the blending of the Fe lines redward of this feature,\ngiving rise to a broad absorption trough, as it was seen in the type\nIc SNe 1997ef (Iwamoto et al. 2000, ApJ 534, 660) and 2002ap (Foley\net al. 2003,  PASP 115, 1220). Further spectroscopic observations are\nencouraged.\"\n\n[GCN OPS NOTE(22feb06): Per author's request, the 2nd author was added.]",
  "circularId": 4809,
  "createdOn": 1140570394000,
  "email": "ajct@iaa.es",
  "subject": "GRB 060218: emergence of the underlying SN spectrum",
  "submitter": "Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct@iaa.es>",
  "eventId": "GRB 060218"
}