{
  "bibcode": "2021GCN.30582....1Z",
  "body": "WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on\nbehalf of the KAIT GRB team:\n\nThe 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at\nLick Observatory, responded to the Swift GRB 210731A (Troja et al.,\nGCN 30568) starting at ~9.04 hours after the Swift trigger.\nA total of 30x60s images were obtained in the clear (roughly R)\nfilter. The optical afterglow (de Wet et al., GCN 30571; Kuin et al.,\nGCN 30572; Guelbenzu et al., GCN 30574; Lipunov et al., GCN 30578;)\nwas clearly detected in each single image. We measured its brightness\nof 18.6 +/- 0.1 mag at 9.26 hours after burst, calibrated to the\nPan-STARRS1 catalog.",
  "circularId": 30582,
  "createdOn": 1627895997000,
  "email": "weikang@berkeley.edu",
  "subject": "GRB 210731A: KAIT Optical Detection",
  "submitter": "Weikang Zheng at UC Berkeley  <weikang@berkeley.edu>",
  "eventId": "GRB 210731A"
}