TITLE: GCN CIRCULAR NUMBER: 41873 SUBJECT: GRB 250916A: KAIT optical observations DATE: 25/09/18 22:13:06 GMT FROM: Weikang Zheng at UC Berkeley <weikang@berkeley.edu> WeiKang Zheng (UCB) and Alexei V. Filippenko (UCB) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, observed the field of GRB 250916A (Fermi GBM team, GCN 41839; Arya et al., GCN 41843; Cheung et al., GCN 41855; Waratkar et al., GCN 41871) starting at ~0.783d and again at ~1.738d after the burst. A set of clear (roughly R) filter images were obtained. We clearly detected the optical afterglow (Belkin et al., GCN 41847; Mohan et al., GCN 41858; Moskvitin et al., GCN 41859; Burkhonov et al., GCN 41860; de Ugarte Postigo et al., GCN 41863; Moskvitin et al., GCN 41870) in our coadd images. We estimate the afterglow to be 19.35 +/- 0.1 and 20.10 +/- 0.1 mag (Vega) at a mid time of ~0.824d and ~1.807d respectively. View this GCN Circular online at https://gcn.nasa.gov/circulars/41873. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...