{
  "bibcode": "2021GCN.30888....1H",
  "body": "K. Hasuda, T. Sakamoto (AGU)\n\nWe observed the field of GRB 210919A detected by Swift\n(Tohuvavohu et al., GCN Circ. 30846) with the iTelescope.Net\n(http://www.itelescope.net) T11 (Planewave 20\" CDK) telescope\nlocated at the New Mexico Skies Observatory (NM, USA).\n59 images of 60 sec exposures were taken in the R filter\nstarting from September 21 on 10:04:47 (UT) about 2.4 days after\nthe trigger and stopped on 11:26:12 (UT).  We further obtained\n60 images of 60 sec exposures in the R filter starting from\nSeptember 22 on 10:01:34.4 (UT) and stopped on 11:27:50 (UT).\n\nWe do not detect the optical afterglow both in the individual\nimages and the stacked image at the XRT position\n(Goad et al., GCN Circ. 30850).  The estimated five sigma\nupper limits of the combined image of the first observation\n(total exposure of 3540 sec) and the second observation (total\nexposure of 3600 sec) are 17.8 and 19.1 using the USNO-B1 catalog.",
  "circularId": 30888,
  "createdOn": 1632734627000,
  "email": "tsakamoto@phys.aoyama.ac.jp",
  "subject": "GRB 210919A: iTelescope T-11 upper limits",
  "submitter": "Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>",
  "eventId": "GRB 210919A"
}