{
  "body": "WeiKang Zheng (UCB) and Alexei V. Filippenko (UCB) report on\n\nbehalf of the KAIT GRB team:\n\n\nThe 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at\n\nLick Observatory, automatically responded to the Swift triggered\n\nGRB 250917B (Caputo et al., GCN 41848; see also Fermi GBM Team,\n\nGCN 41846) starting at 06:29:01 UT, 77 seconds after the burst.\n\nA set of 10x20s, 10x40s and 50x60s clear (roughly R) filter images\n\nwere obtained. We do not detect any new uncataloged source around\n\nSwift-XRT sources 1, 5 or 6 (Kennea et al., GCN 41851) neither in\n\nsingle image nor in coadd images. We estimate the limiting mag of\n\n~21.5 (Vega) at a mid time of 45 minutes after the burst in our\n\ncoadd image.\n",
  "eventId": "GRB 250917B",
  "circularId": 41927,
  "createdOn": 1758443500866,
  "submittedHow": "email",
  "bibcode": "2025GCN.41927....1Z",
  "submitter": "Weikang Zheng at UC Berkeley <weikang@berkeley.edu>",
  "subject": "GRB 250917B: KAIT optical upper limit"
}