TITLE: GCN CIRCULAR NUMBER: 32894 SUBJECT: GRB 221028A: AKO Optical Upper Limit DATE: 22/10/30 20:24:14 GMT FROM: Mohammad Odeh at Al Khatim Observatory M44 mshodeh@gmail.com
Mohammad Odeh at Al-Khatim Astronomical Observatory (AKO), operated by the International Astronomical Center (IAC), in Abu Dhabi, the United Arab Emirates.
We observed the GRB 221028A (Lien et al., GCN 32874) with our 0.36m telescope on 30 October from 15:39 to 16:44 (UT). We obtained exposures in the B, V, and Ic filters and did not detect any afterglow within XRT localization (Lien et al., GCN 32874). This is consistent with the reported non-detections of (Hu et al., GCN 32878; Lipunov et al., GCN 32879; Strausbaugh et al., GCN 32881; Niwano et al., GCN 32883; Kumar et al., GCN 32886; Watson et al., GCN 32888; Belkin et al., GCN 32889).
Each image consists of seven stacked frames, each frame is a 3-minute exposure. The obtained upper limits are as follows:
Mid Time (UT), Filter, Lim. Mag.
2022-10-30T16:16:06Z, B, > 18.3
2022-10-30T16:13:03Z, V, > 19.6
2022-10-30T16:09:22Z, Ic, > 20.2