{
  "bibcode": "2002GCN..1273....1G",
  "body": "P. M.  Garnavich, S. T. Holland (Notre Dame), S. Jha, R. P. Kirshner, \n   D. Bersier, and K. Z. Stanek (CfA)\n\nWe have reanalyzed R-band images of GRB 011121 obtained with the\nWalter Baade 6.5m Magellan telescope on 2001 Dec. 4.32  in light\nof the recently released HST images taken near the same time\n(Bloom, GCN 1260). The brightness of the afterglow in the Magellan\ndata deviated from the steep powerlaw decline seen in the\nfirst three days after the burst and we attributed this to contamination\nfrom the host galaxy (e.g. Phillips et al. GCN 1164). However the Magellan\nmagnitude of R=23.0+\\-0.1, obtained by point-spread-function fitting is\nconsistent with the WFPC2 magnitude of f702w=23.16+\\-0.08 which\nhas minimal host contamination. Both observations are nearly\n2 magnitudes brighter than the early-time extrapolation. \n\nThe full light curve is well fit by an initial powerlaw with\nindex of 1.71+\\-0.05  plus the light curve of SN 1998bw stretched\nand faded to a redshift of z=0.36 (Infante et al. GCN 1152). The\nDec. 4 data is 10 days after explosion in the rest frame, while\nSN 1998bw peaked 17 days after GRB 980425, so later epochs\nmay show a small rise in the f702w magnitude before final\nfading. The light curve can be viewed at\n\nhttp://www.nd.edu/~pgarnavi/grb011121/grb011121_sn.ps\n\nAssuming a flat cosmology with Omega_m=0.3 and a Hubble\nparameter of 65 km/s/Mpc, we derive an absolute magnitude for\nthe possible supernova on Dec. 4 of Mv=-19.3+\\-0.2 (corrected\nfor a large Galactic extinction but not for host extinction), consistent\nwith SN 1998bw near maximum.  These observations could be strong\nevidence for a SN-GRB connection.\n\nThis message may be cited.",
  "circularId": 1273,
  "createdOn": 1016212571000,
  "email": "pgarnavi@miranda.phys.nd.edu",
  "subject": "GRB011121, possible supernova association",
  "submitter": "Peter Garnavich at U of Notre Dame  <pgarnavi@miranda.phys.nd.edu>",
  "eventId": "GRB 011121"
}