{
  "bibcode": "2004GCN..2904....1K",
  "body": "GRB 041218: Optical observations\n\nKlotz, A., Boer M. (OHP), Atteia, J.L., and G. Stratta (LATT) report:\n\nThe field of GRB 041218 (Mereghetti, et al., GCNC 2858) was observed with\nthe TAROT 25 cm robotic telescope at Calern, France.\nThe unfiltered observations started at 2004 December 18 17:12 UT (beginning\nof the night). Due to a technical problem images were slightly defocused.\n\nWe co-added 129 frames of 30s from 17:12 to 18:50 UT.\nThe associated OT described by Torii (GCNC 2860) is detected 0.5 mag fainter\nthan the nearby star USNO-B1 1613-0027278.\nHence, we estimate its magnitude, R = 19.4 +/- 0.2.\n\nWe analyzed the 2MASS catalogue to extract the galactic extinction through\nthe line of sight of GRB041218. We used the method described in Klotz et al.\n(A&A 2004, vol 425, p427). From Earth to a distance modulus of about 8, the\nvisual extinction is Av=1.45. The 2MASS data doesn't allow probing farer\ndistances.\n\nThis message can be cited.",
  "circularId": 2904,
  "createdOn": 1103896717000,
  "email": "Michel.Boer@oamp.fr",
  "subject": "GRB 041218: TAROT optical observations",
  "submitter": "Michel Boer at Obs Haute Prov.  <Michel.Boer@oamp.fr>",
  "eventId": "GRB 041218"
}