{
  "bibcode": "2004GCN..2879....1D",
  "body": "Paolo D'Avanzo, Stefano Ciroi, Daniele Malesani, Stefano Covino, \nVincenzo Testa, and Angelo Antonelli, report on behalf of a larger \nItalian collaboration:\n\n\"We observed the field of GRB041218 (Mereghetti et al., GCN 2858) \nstarting about 6 hours after the trigger. Observations were performed \nwith the 182cm Copernicus telescope equipped with the AFOSC instrument, \nat the Asiago Observatory (Northern Italy). Weather conditions were not \noptimal, with a seeing of 3\". We detected the optical afterglow in the R \nfilter (Torii, GCN 2860; Gorosabel et al., GCN 2861), with the following \nmagnitudes (based on the calibration provided by Henden, GCN 2869):\n\nUT (mean)   t-t0*  mag    error\n-------------------------------\nDec 18.912  6.1 h  21.37  0.15\nDec 19.061  9.7 h  22.41  0.46\n\nt0 = Dec 18.6565 UT (burst explosion time).\n\nIn the last epoch, the object is barely visible, but clearly faded since \nthe first epoch. Our results are consistent with those reported by Greco \net al. (GCN 2863), Halpern & Tuttle (GCN 2873) and Monfardini et al. \n(GCN 2878). Using all the available data, the decay index is alpha ~ 1.4 \n(F=K*t^-alpha) from ~2 to ~13 hours after the GRB. When comparing with \nthe earliest measurement from Torii (GCN 2860), a steepening in the \nlight curve is apparent.\n\nThis message can be cited.",
  "circularId": 2879,
  "createdOn": 1103491637000,
  "email": "malesani@sissa.it",
  "subject": "GRB 041218: R-band optical observations",
  "submitter": "Daniele Malesani at SISSA-ISAS,Trieste,Italy  <malesani@sissa.it>",
  "eventId": "GRB 041218"
}