{
  "bibcode": "2008GCN..8266....1R",
  "body": "A. Rossi (Tautenburg Obs.),T. Kruehler, J. Greiner, A. Yoldas, C. Clemens,\n R. 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 080916A (Ziaeepour et al. GCN #8237) in g'r'i'z'JHK at \n23:57:34 UT on 2008-09-16, 14 hours after the burst trigger.\n\nWe clearly detect the optical afterglow detected by UVOT (Ziaeepour \net al. GCN #8237) and REM telescope (Fugazza et al. GCN #8238). \nObservations continued for 60 min and were repeated at the mid-time \n06:40 UT for total 60 min.\n\nCalibrating the field on USNO-B1 stars, we derive the following\nr band magnitudes, not corrected for the Galactic foreground \nextinction corresponding to a reddening of E_(B-V)=0.019 mag \n(Schlegel et al. 1998):\n\nmidtime(s)\tr\ter\n52239       \t21.8\t0.03\n54054       \t21.9\t0.04\n74076       \t22.1\t0.07\n76260        \t22.3\t0.07\n\nThe total r band light curve is well fitted by power law with index \nof 0.81+- 0.13. Assuming the optical light curve continues \nthe decline with the same power law index, we predict r' \nband magnitudes 23.4 at 3 days after the burst.",
  "circularId": 8266,
  "createdOn": 1221736996000,
  "email": "rossi@tls-tautenburg.de",
  "subject": "GRB 080916A: GROND lightcurve",
  "submitter": "Andrea Rossi at TLS Tautenburg  <rossi@tls-tautenburg.de>",
  "eventId": "GRB 080916A"
}