{
  "bibcode": "2013GCN.14639....1S",
  "body": "S. Schmidl, D. A. Kann (both TLS Tautenburg) and J. Greiner (MPE Garching)\nreport on behalf of the GROND team:\n\nWe observed the field GRB 130513A (INTEGRAL trigger 6842; Mereghetti et\nal., GCN 14630) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al.\n2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla\nObservatory (Chile).\n\nObservations started in twilight at 22:54:57 UT on May 13th, 15.3 hours\nafter the IBAS trigger. They were performed at an average seeing of 1\".0\nand at an average airmass of 1.1.\n\nInside the 2\".7 refined XRT error circle (Evans et al., GCN 14635), we do\nnot detect any sources. Based on an observation with 1500 s integration\ntime in g'r'i'z' and 1200 s integration time in JHK, centered at 0.6959\ndays after the trigger, we estimate preliminary 3-sigma upper limits (all\nin AB system) of\n\ng' > 25.4,\nr' > 24.9,\ni' > 24.2,\nz' > 23.9,\nJ  > 21.4,\nH  > 20.6 and\nK  > 20.2.\n\nWe note that if the XRT source is indeed the afterglow, then it is very\nfaint optically. Galactic extinction is negligible.\n\nGiven magnitudes are calibrated against GROND zero points (g'r'i'z') as\nwell as 2MASS field stars (JHK) and are not corrected for the expected\nGalactic foreground extinction corresponding to a reddening of\nE_(B-V)=0.03 mag in the direction of the burst (Schlegel et al. 1998).",
  "circularId": 14639,
  "createdOn": 1368548457000,
  "email": "kann@tls-tautenburg.de",
  "subject": "GRB 130513A: GROND observations",
  "submitter": "Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>",
  "eventId": "GRB 130513A"
}