TITLE: GCN CIRCULAR NUMBER: 45716 SUBJECT: GRB 260922A: CALET Gamma-Ray Burst Monitor detection DATE: 26/09/24 05:34:09 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University S. Ricciarini (U of Florence), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC), M. L. Cherry (LSU), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The CALET Gamma-ray Burst Monitor (CGBM) detected GRB 260922A at 10:00:33.96 UTC on 22 September 2026 (trigger #1474106408; https://cgbm.calet.jp/cgbm_trigger/flight/1474106408/index.html). A CGBM Notice was distributed in near real time. This event was also reported by Swift-BAT (Page et al., GCN #45690; Sakamoto et al., GCN #45703) . The burst signal was seen by only the SGM detector. The burst light curve shows a double-peaked structure starting at T+0.4 s, peaking at T+5.8 s, and ending at T+ 7.5 s. The T90 and T50 durations measured with the SGM data are 6.2 +/- 0.5 s and 2.8 +/- 0.4 s in the 40-1000 keV band, respectively. The ground-processed light curve is available at: https://cgbm.calet.jp/cgbm_trigger/ground/1474106408/ The CALET data used in this analysis were provided by the Waseda CALET Operation Center located at Waseda University.