{
  "bibcode": "2008GCN..8296....1R",
  "body": "A. Rossi (Tautenburg Obs.), C. Clemens, J. Greiner, A. Yoldas, T. Kruehler,\nR. Filgas (all MPE Garching), A. Kupcu Yoldas (ESO) and\nG. Szokoly (Eoetvoes Univ., Budapest) report on behalf of the GROND team:\n\nGROND (Greiner et al. 2008, PASP 120, 405),  mounted at the 2.2m ESO/MPI\ntelescope at La Silla Observatory (Chile), started observations of the\nfield of GRB 080928 (Sakamoto et al. GCN #8292) in g'r'i'z'JHK at\n04:46:00 UT on 2008-09-29, 13.5 hours after the burst trigger.\n\nWe clearly detect the optical afterglow detected by UVOT (Sakamoto et al.\nGCN #8292) and ROTSE telescope (Rykoff et al. GCN #8293) in\nall optical bands, implying a redshift z<3.5.\n\nObservations continued for 90 min and were repeated at the mid-time\n06:00 UT for a total 90 min. Both observations were done during strong wind\nand bad seeing (>2\").\n\nCalibrating the field on the SDSS standard SA95-149, we derive the following\nr' band observed magnitudes:\n\n  midtime(s)    r'    err\n------------------------\n50507        20.57    0.04   \n65807        21.36    0.06   \n\nOur data, when compared to the reported brightness of the afterglow\nreported by UVOT, suggest a break between the UVOT and the GROND\nmeasurements.",
  "circularId": 8296,
  "createdOn": 1222689724000,
  "email": "rossi@tls-tautenburg.de",
  "subject": "GRB 080928: GROND DETECTION",
  "submitter": "Andrea Rossi at TLS Tautenburg  <rossi@tls-tautenburg.de>",
  "eventId": "GRB 080928"
}