{
  "bibcode": "1999GCN...462....1M",
  "body": "N. Masetti, E. Palazzi, E. Pian, F. Frontera (ITESRE, CNR, Bologna), \nS. Benetti, A. Magazzu' (TNG), A.J. Castro-Tirado (LAEFF-INTA and \nIAA-CSIC) and B.L. Jensen (Univ. of Copenhagen), on behalf of a\nlarger collaboration, report:\n\n\n\"R images of the optical afterglow of GRB991208 (GCN #452 and #453) were\nobtained between Dec. 12.29 and Dec. 15.29 UT at Roque de Los Muchachos\n(Canary Islands, Spain) with the 3.58-meter Telescopio Nazionale Galileo\n(TNG) + OIG CCD camera. We clearly detected the optical transient in all\nR images. The following table shows the results of these observations:\n\n\n     Date (UT)       Exptime      Magnitude     Seeing\n\t\t\t\t\t \t     \n\n  1999 Dec 12.29     500 sec    20.25 +- 0.15    1\".8\n  1999 Dec 13.29     360 sec    20.3  +- 0.2     1\".6\n  1999 Dec 14.29     600 sec    21.25 +- 0.15    1\".5\n  1999 Dec 15.29     900 sec    21.6  +- 0.3     1\".5 (clouds)\n\n\nPhotometric calibration was tied to the USNO A2.0 star 1350-08916561\n(R = 15.85 +- 0.1 was assumed).\nPreliminary analysis of R data shows that these are consistent with a\npower-law decay with index alpha = -2.15 (GCN #454 and #456) with the\nexception of the observation of Dec. 13.29, which may however be affected\nby uncertainties associated with the observing conditions and with the\nshorter exposure time.\"\n\n\nThis message can be cited.",
  "circularId": 462,
  "createdOn": 945359166000,
  "email": "masetti@tesre.bo.cnr.it",
  "subject": "R-band Observations of GRB991208 at TNG",
  "submitter": "Nicola Masetti at ITeSRE,CNR,Bologna  <masetti@tesre.bo.cnr.it>",
  "eventId": "GRB 991208"
}