{
  "bibcode": "2017GCN.22166....1I",
  "body": "L. Izzo, D. A. Kann, A. de Ugarte Postigo (all HETH/IAA-CSIC), and V. Casanova (IAA-CSIC)  report:\n\nWe observed the field of GRB 171123A  (Evans et al.; GCN Circ. 22148) with the 1.5-m OSN telescope in Granada, Spain.\n\nWe began observing at 03:32:53 UT (13.3 hours after the GRB trigger), and obtained 18x300s images in the Ic band. Observations were obtained in inclement conditions (clouds, bad seeing of ~2\")  and the last four images could not be used.\n\nIn our stacked image, we find no source at the position reported by Schmidl et al. (GCN Circ. 22162) down to a a 3-sigma limit of Ic (Vega) > 21.  The calibration was performed using nearby stars in the USNO B1 catalog.",
  "circularId": 22166,
  "createdOn": 1511549557000,
  "email": "Luca.Izzo@ICRA.it",
  "subject": "GRB 171123A: OSN Upper Limit",
  "submitter": "Luca Izzo at IAA-CSIC  <Luca.Izzo@ICRA.it>",
  "eventId": "GRB 171123A"
}