TITLE: GCN CIRCULAR NUMBER: 44817 SUBJECT: GRB 260601A: CALET Gamma-Ray Burst Monitor detection DATE: 26/06/04 08:23:39 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp> K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU), 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), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The CALET Gamma-ray Burst Monitor (CGBM) detected the short GRB 260601A at 11:00:12.042 UTC on 1 June 2026 (trigger #1464346716; https://cgbm.calet.jp/cgbm_trigger/flight/1464346716/index.html). A CGBM Notice was distributed in near real time. This event was also reported by Fermi GBM (The Fermi GBM team, GCN #44755; Holzmann Airasca et al., GCN #44760), Glowbug (Cheung et al., GCN #44763), GECAM-B (Wang et al., GCN #44778), SVOM/GRM (Wang et al., GCN #44793), and KONUS-Wind (IPN_RAW Notice at 2026-06-01 11:00:09.16 UTC). The burst signal was seen by all CGBM detectors. The burst light curve shows a multi-peaked structure, starting at T+0.40 s, peaking at T+0.50 s, and ending at T+0.59 s. The T90 and T50 durations measured with the SGM data are 0.18 +/- 0.01 s and 0.05 +/- 0.03 s in the 40-1000 keV band, respectively. The ground-processed light curve is available at: https://cgbm.calet.jp/cgbm_trigger/ground/1464346716/ The CALET data used in this analysis were provided by the Waseda CALET Operation Center located at Waseda University. View this GCN Circular online at https://gcn.nasa.gov/circulars/44817. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...