{
  "bibcode": "2018GCN.23238....1T",
  "body": "Eleonora Troja (GSFC), Alan M. Watson (UNAM), Nat Butler (ASU),\nAlexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer\n(UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),\nAntonino Cucchiara (UVI), , Owen Littlejohns (ASU), Enrico\nRamirez-Ruiz (UCSC), Jesus Gonzalez (UNAM), Carlos Roman-Zuniga (UNAM),\nHarvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.),\nand Vicki Toy (UMD) report:\n\nWe observed the field of GRB 180914B, detected by AGILE/MCAL (Ursi,\net al., GCN 23226) AGILE/GRID (Verrecchia, et al., GCN 23231), and\nFermi/LAT (Bissaldi, et al., GCN 23232) with the Reionization and\nTransients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold\nJohnson Telescope at the Observatorio Astronomico Nacional on Sierra\nSan Pedro Martir from 2018/09 16.14 to 2018/09 16.16 UTC (32.90 to\n33.43 hours after the burst), obtaining 0.36 hours exposure in the\nr and i bands and 0.15 hours exposure in the Z, Y, J, and H bands.\n\nWithin the Swift-XRT error circle (D'Ai, et al., GCN 23236),\nwe detect the object reported by Zheng & Filippenko (GCN 23237).\nIn comparison with the SDSS DR9 and 2MASS catalogs, we obtain\nthe following detections:\n\nr = 19.51 +/- 0.01\ni = 19.20 +/- 0.01\nz = 18.93 +/- 0.03\nY = 18.75 +/- 0.03\nJ = 18.60 +/- 0.05\nH = 18.28 +/- 0.04\n\nThese magnitudes are in the AB system and are not corrected for Galactic\nextinction in the direction of the GRB.\n\nThe source position is consistent with a catalogued SDSS galaxy with\nphotometric redshift z~0.58. However, its brightness is significantly\nhigher than the values reported in the catalogue,suggesting that the\nemission may be dominated by the GRB afterglow and that the SDSS\nobject may be the GRB host galaxy.\n\nFurther observations to establish the source variability are planned.\n\nWe thank the staff of the Observatorio Astronomico Nacional in San Pedro\nMartir.",
  "circularId": 23238,
  "createdOn": 1537076892000,
  "email": "eleonora.troja@nasa.gov",
  "subject": "GRB 180914B: RATIR Optical and NIR Observations",
  "submitter": "Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>",
  "eventId": "GRB 180914B"
}