{
  "bibcode": "2018GCN.22714....1B",
  "body": "J. Bolmer MPE Garching) reports on behalf of the GROND Team:\n\nI observed the field of GRB180512A (Swift trigger 832119; Deich et\nal., GCN #22710) 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\nObservations started at 00:03 UT on 2018-05-13, 2.7 hrs after the GRB\ntrigger. They were performed at an average seeing of 1.3'' and at an\naverage airmass of 1.9.\n\nNo source is detected within or close to the Swift-XRT error circle.\n\nBased on 40 min of exposure in g'r'i'z' and 41 min in JHK_s, at a mid-time\nof 00:44 UT, we derive the following preliminary upper\nlimits (in AB system):\n\ng' > 25.4 mag,\nr' > 24.9 mag,\ni' > 24.0 mag,\nz' > 23.4 mag,\nJ > 21.9 mag,\nH > 21.2 mag, and\nK_s > 20.2 mag.\n\nGiven upper limits are calibrated against SDSS field stars in g'r'i'z'\nas well as 2MASS field stars in JHK_s. No correction for the expected Galactic\nforeground extinction corresponding to a reddening of E_(B-V)=0.058 mag in\nthe direction of the burst (Schlafly & Finkbeiner 2011) has been applied.",
  "circularId": 22714,
  "createdOn": 1526179352000,
  "email": "jan@bolmer.de",
  "subject": "GRB 180512A: GROND upper limits",
  "submitter": "Jan Bolmer at MPE/Garching  <jan@bolmer.de>",
  "eventId": "GRB 180512A"
}