{
  "bibcode": "2021GCN.30934....1O",
  "body": "B. O'Connor (UMD, GWU),E. Hammerstein (UMD),S.B. Cenko (UMD,\nNASA-GSFC),E. Troja (UMD, NASA-GSFC),A.Gottlieb (UMD,\nNASA-GSFC),S.Dichiara (PSU),A. Kutyrev (UMD,NASA-GSFC),\nS. Veilleux (UMD)\n\nWe observed the field of GRB 210919A (Tohuvavohu et al., GCN 30846)\nusing the Large Monolithic Imager (LMI) on the 4.3m Lowell Discovery\nTelescope (LDT) at Happy Jack, AZ. Observations started on October 11,\n2021 at 11:39:44 UT (~3 weeks after the GRB trigger), and were carried\nout in r-band for 5x300 s exposures. The observations were performed at\nairmass 1.2 with seeing 0.8\".\n\nAt the position of the optical source reported by Kann et al.\n(GCNs 30883 and 30884) we do not detect any source down to a\n3-sigma upper limit of r>25.1 AB mag. However, within the XRT\nenhanced position (Goad et al., GCN 30850), we detect a source\nwith magnitude r~24.0+/-0.1 AB mag at position\nRA, DEC = 05:21:00.87,+01:18:42.68 +/- 0.5\",\nwhich is 3.4\" offset from the Kann et al. source (GCNs 30883 and 30884).\n\nThe source appears marginally extended although it cannot be\nconfidently associated with GRB 210919A due to the high probability\nof chance coincidence of Pcc=0.45 (Bloom et al. 2002). We also note\nthe presence of a bright galaxy (also seen in SDSS)\nwith r~20.47+/-0.05 mag at an offset of ~13\" from the XRT localization.\nThis galaxy has a photometric redshift z~0.27+/-0.12, and probability\nof chance coincidence is Pcc=0.15.\n\nMagnitudes are calibrated against the SDSS catalog and are not corrected\nfor Galactic extinction.\n\nWe thank the staff of the Lowell Discovery Telescope for assistance\nwith these observations.",
  "circularId": 30934,
  "createdOn": 1634080470000,
  "email": "oconnorb@umd.edu",
  "subject": "GRB 210919A: LDT optical observations and candidate host galaxies",
  "submitter": "Brendan O'Connor at UMD  <oconnorb@umd.edu>",
  "eventId": "GRB 210919A"
}