{
  "bibcode": "2002GCN..1505....1D",
  "body": "A. Di Paola (1), A. Arkharov (2), V. Larionov (3),\nL. A. Antonelli (1)\n\n1) Rome Astronomical Observatory (IT)\n2) Pulkovo Observatory (RU)\n3) St.Petersburg University (RU)\n\non the behalf of the GROAR Team, report:\n\nWe have imaged the GRB020813 OT (GCN 1471) from the\nCampo Imperatore Observatory both with the 60cm\nSchmidt telescope at optical wavelengths and with\nthe 1.1 meters AZT-24 telescope at NIR wavelengths.\n\nObservations started on 2002-08-13 19:50:00 UT\nand ended the same day on 23:52:00 UT, respectively\n16.1 and 21.1 hours after the burst.\n\nThe extremely low elevation (always between 2 and 3\nairmasses) and the consequent poor seeing conditions\nallow us to barely distinguish between the OT and the\ndouble star located about 3.8\" to the North (see\nU. Kiziloglu et al. GCN 1488, W. D. Li et al. GCN 1491,\nM. Gladder et al. GNC 1495). For this reason the following\nmagnitudes have to be considered lower limits until\nwe will complete the subtraction of the field components.\n\nWe obatined V, R, I, J and K images at:\n2002-08-13 19.42 V-band: OT ~ 19.90 +- 0.20\n2002-08-13 19.77 R-band: OT ~ 18.85 +- 0.20\n2002-08-13 20.49 I-band: OT ~ 19.90 +- 0.20\n2002-08-13 21.61 R-band: OT ~ 19.70 +- 0.20\n2002-08-13 22.88 V-band: OT ~ 20.35 +- 0.20\n2002-08-13 23.38 I-band: OT ~ 20.15 +- 0.20\nand a continuous repetition of J and K images\nstarting from 18.83 up to 23.88 UT.\n\nWe extimated the color indexes between optical and\nNIR bands:\n  V-J ~ 1.3 +- 0.5\n  V-K ~ 3.1 +- 0.5\nand the magnitudes at J and K to be about 18.8 and\n17.0 respectively.\n\nThe magnitudes calibration is obtained from\nA. Henden GCN 1503 for the optical points and from\n2MASS catalog for the infrared points.\n\nThe refined analysis is underway.",
  "circularId": 1505,
  "createdOn": 1029748195000,
  "email": "dipaola@mporzio.astro.it",
  "subject": "GRB020813: optical and NIR observations",
  "submitter": "Andrea Di Paola at Rome Astron.Obs.-INAF  <dipaola@mporzio.astro.it>",
  "eventId": "GRB 020813"
}