{
  "bibcode": "2002GCN..1520....1K",
  "body": "S. Klose (Thueringer Landessternwarte Tautenburg),\nA. Henden (USRA/USNO),\nJ. Greiner (MPE Garching), \nD. H. Hartmann (Clemson University),\nN. Cardiel, J. Gallego (Universidad Complutense de Madrid), and\nU. Thiele (Calar Alto Observatory)\n \nreport:\n\nA deep second epoch K' band observation of the 130 arcsec radius error \ncircle of the HETE burst GRB 020819 (HETE trigger #2275, Seq_4; \nVanderspek et al. 2002, GCN #1508) has been performed on August 20/21, \n23:11--00:59 UT (about 33 hrs after the GRB), using the Calar Alto \n3.5-m telescope equipped  with the Omega Prime near-infrared camera. \nThe integration time was 77 min. The limiting magnitude is about \nK'=20.5 (+/-0.5), the seeing was 1.2 arcsec.\n\nLacking a K band photometric calibration, we used the (B-R) colors of all \nUSNO stars (Monet et al. 1996; http://asteroid.lowell.edu/cgi-bin/koehn/webnet)\nin the field for a rough calibration. Assuming their colors are \nrepresentative for their spectral type and assuming zero interstellar \nextinction, the magnitude of the candidate object reported in GCN #1510 \n(Henden et al. 2002) is found to have K'=17.6 (conservative error of 0.2 mag).\n\nPhotometry of all objects within the HETE/SXC error circle using PSF fitting\n(Sextractor) did not reveal any source brighter than K'=19 which faded by \nmore than 0.1 mag between the first epoch (Henden et al. 2002, GCN #1510)\nand this second epoch observation. This and the findings of Price et al.\n2002 (GCN #1511) and Salamanca et al. 2002 (GCN #1512) imply that the \ncandidate object proposed earlier (Henden et al. 2002, GCN #1510) is very\nunlikely the GRB afterglow.",
  "circularId": 1520,
  "createdOn": 1030093398000,
  "email": "jcg@mpe.mpg.de",
  "subject": "Second epoch K band imaging of GRB 020819",
  "submitter": "Jochen Greiner at MPI  <jcg@mpe.mpg.de>",
  "eventId": "GRB 020819"
}