{
  "bibcode": "2016GCN.19385....1K",
  "body": "T. Kruehler (MPE Garching), A. de Ugarte Postigo (IAA-CSIC and\nDARK/NBI), and T. Kuutma (NOT) report on behalf of a larger\ncollaboration:\n\nWe observed the field of GRB 160504A (Malesani et al., GCN #19382)\nwith the NOT equipped with ALFOSC. Imaging in the r, i and z-band\nfilter started at 20:54:10 UT on 2016-05-04, 1.4 hr after the GRB\ntrigger.\n\nWe detect no sources in the enhanced XRT error circle given at\nhttp://www.swift.ac.uk/sper/685124/.\n\nCalibrating our images against magnitudes from field stars of the\nSDSS catalog, we measure preliminary upper limits of\n\nr > 23.3 mag\ni > 22.8 mag\nz > 22.0 mag\n\nThese limits are not corrected for the expected foreground\nextinction corresponding to a reddening of E(B-V) = 0.01 mag\n(Schlafly & Finkbeiner 2011).",
  "circularId": 19385,
  "createdOn": 1462400525000,
  "email": "kruehler@mpe.mpg.de",
  "subject": "GRB 160504A: NOT upper limits",
  "submitter": "Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>",
  "eventId": "GRB 160504A"
}