{
  "bibcode": "2003GCN..2107....1M",
  "body": "T. Matheson (CfA), P. Garnavich (Notre Dame), N. Hathi, R. Jansen,\nR. Windhorst, L. Echevarria (ASU), J. Lee (Arizona), W. Brown,\nN. Caldwell, P. Berlind. M. Calkins and K. Z. Stanek (CfA) report:\n\nWe obtained spectra of the afterglow of GRB 030329 (Peterson & Price,\nGCN 1985; Torii: GCN 1986) with the 6.5-m MMT and Blue-Channel\nspectrograph each night from March 30.12 to April 6.15 (UT). The\nspectra cover a wavelength range of 350 nm to 850 nm with a resolution\nof 0.6 nm (FWHM). The early spectra consist of a power-law continuum\nwith narrow emission lines originating from HII regions in the host\ngalaxy (Martini et al. GCN 2013; Della Ceca et al. GCN 2015; Greiner\net al. GCN 2020; Caldwell et al. GCN 2053).  However, our spectrum\ntaken Apr. 6.15 (UT) shows a broad peak in flux at approximately 570\nnm and another weak deviation from a power-law near 470nm that were\nnot evident in the earlier spectra.\n\nThe April 6 spectrum is well reproduced by adding a spectrum of SN\n1998bw (Patat et al. 2001, ApJ, 555, 900) seven days before maximum\nlight to a power-law distribution. We conclude that a supernova\nspectrum is emerging from the afterglow light.  The brightness of the\nsupernova is approximately V=22 based on the strengths of the broad\nfeatures relative to a pure power-law. Further spectroscopy is\nplanned.\n\nA plot of the spectrum compared with SN 1998bw is available at:\nhttp://cfa-www.harvard.edu/~tmatheson/grb030329_sn.jpg\n\nThis message may be cited.",
  "circularId": 2107,
  "createdOn": 1049680485000,
  "email": "kstanek@cfa.harvard.edu",
  "subject": "GRB 030329: Supernova Spectrum Emerging",
  "submitter": "Krzysztof Z. Stanek at CfA  <kstanek@cfa.harvard.edu>",
  "eventId": "GRB 030329"
}