{
  "bibcode": "2016GCN.19144....1G",
  "body": "J. Graham, J. Bolmer, P. Wiseman and J. Greiner (all MPE Garching) report on\nbehalf of the GROND team:\n\nWe observed the field of GRB 160303A (Swift trigger 677495; Beardmore et\nal., GCN #19126) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.\n2008, PASP 120, 405) mounted at the 2.2m MPG telescope at the ESO La Silla\nObservatory (Chile)./\n/Observations started at 03:27 UT on 2016-03-04, 16.5h after the GRB\ntrigger. They were performed at an average seeing of 1.3\" and at an\naverage airmass of 1.6./\n/We detect a single source at the edge of the Swift-XRT error circle\nreported by Evans et al. (GCN #19132) consistent with the optical \ncandidate from de Ugarte Postigo et al. (GCN #19136) and Klose et al. \n(GCN #19142)/\n/Based on 66 min of exposure in g'r'i'z' and 60 min in JHK, at a mid-time\nof 04:54 UT, we derive the following preliminary magnitudes and upper\nlimits (in AB system):/\n/g' = 24.2 +/- 0.1 mag,\nr' = 24.0 +/- 0.1 mag,\ni' = 23.9 +/- 0.2 mag,\nz' = 23.5 +/- 0.3 mag,\nJ > 21.1 mag,\nH > 20.1 mag, and\nK > 19.5 mag./\n/Given detections and upper limits are calibrated against SDSS\nas well as 2MASS field stars. No correction for the expected Galactic\nforeground extinction corresponding to a reddening of E_(B-V)=0.014 mag in\nthe direction of the burst (Schlafly & Finkbeiner 2011) has been applied.\n\n-- \nPhilip Wiseman                 wiseman@mpe.mpg.de\nDoctoral Student  \t       +49 (0)89 30000-3566\nGRB Group\t               +49 (0)1605 011752\n\nIMPRS Student Representative\n\nRoom X5 1.3.09\nMax-Planck-Institute fuer extraterrestriche Physik\nGiessenbachstrasse 1\n85748 Garching, Germany",
  "circularId": 19144,
  "createdOn": 1457109205000,
  "email": "wiseman@mpe.mpg.de",
  "subject": "GRB 160303A: GROND Optical Detection",
  "submitter": "Philip Wiseman at MPE/Swift  <wiseman@mpe.mpg.de>",
  "eventId": "GRB 160303A"
}