{
  "bibcode": "2006GCN..4705....1M",
  "body": "F. Malacrino & JL. Atteia (LA-OMP) report on behalf of the GRB Real Time\nAnalysis System at CFHT (http://www.cfht.hawaii.edu/~grb/).\n\nWe observed an unusual optical transient recorded within the course of\nthe Very-Wide Survey of the CFHTLS (http://www.cfht.hawaii.edu/Science/CFHLS/ ).\n\nWe consider that this transient is a possible GRB afterglow.\n\nThe transient is stationary and detected in a series of three consecutive\n180s long i' band exposures taken on the night of February 2nd, 2006.\nThe transient is not seen in a 180s long i' band exposure taken\non the following night.\n\nThe magnitudes of the transient are :\n\n02-02-2006, 26797s, i�= 20.8 � 0.2\n02-02-2006, 30060s, i�= 20.7 � 0.2\n02-02-2006, 33207s, i�= 20.6 � 0.2\n\n03-02-2006, 27802s, i' > 23.0\n\n\nThe coordinates (J2000) of the transient are:\n\nRA = 05 07 33.83 � 0.5\"\nDEC = +22 17 10.9 � 0.5�\n\nA finding chart can be found at the following address:\nhttp://www.cfht.hawaii.edu/~grb/double/06AQ01/836441o836294o/glo.html#N03CCD26\nthe transient is seen in the leftmost image.\n\nWe have no color information on the transient.\n\n\nWe have perfomed the following verifications to check the possible nature\nof this object:\n\n- There is no object in the USNO-B1 Catalog (Monet 2003) at this position.\n\n- There is no object at this position in all the VizieR catalogs\n    (http://vizier.u-strasbg.fr/viz-bin/VizieR)\n\n- There is no object at this position in the DSS or 2MASS images.\n\n- There is no detectable source at this position in archival images\n    taken at the CFHT in g' band (there are no archival images in the i'\nband).\n\n\nTo date, after 1.5 years of operation, this object is our best candidate\nfor a GRB afterglow. If this is truly a GRB afterglow, we note that\nthe fast decrease of the source between the nights of February 2nd and 3rd\nimplies that we have caught the afterglow a few hours only after the GRB.\n\nWe strongly encourage follow-up observations at all wavelengths,\nespecially in X-rays and radio given the age of the afterglow (5 days),\nand also in IR since the source was detected in the i' band.\n\n\nBased on observations obtained with MegaPrime/MegaCam, a joint project of\nCFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is\noperated by the National Research Council (NRC) of Canada, the Institut\nNational des Sciences de l'Univers of the Centre National de la Recherche\nScientifique (CNRS) of France, and the University of Hawaii.\n\n[GCN OPS NOTE(05feb06): Per author's request, the last paragraph was added.]",
  "circularId": 4705,
  "createdOn": 1139327709000,
  "email": "atteia@ast.obs-mip.fr",
  "subject": "Orphan GRB Afterglow candidate",
  "submitter": "Jean-Luc Atteia at Lab d Astrophys.,OMP,Toulouse  <atteia@ast.obs-mip.fr>"
}