TITLE: GCN CIRCULAR NUMBER: 42321 SUBJECT: GRB 251016A: CALET Gamma-Ray Burst Monitor detection DATE: 25/10/17 07:26:43 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp> Y. Kawakubo , A. Yoshida, T. Sakamoto, S. Sugita (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/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The short GRB 251016A (SVOM detection: Basa et al., GCN Circ. 42308; Fermi GBM Final Localization: Fermi GBM team, GCN Circ. 42309; Glowbug gamma-ray detection: Woolf et al., GCN Circ. 42313) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 14:59:19.37 UTC on 16 October 2025 (https://cgbm.calet.jp/cgbm_trigger/flight/1444661491/index.html). The burst signal was seen by all CGBM detectors. The burst light curve shows a short pulse that starts at T+0.32 sec, peaks at T+0.51 sec, and ends at T+0.69 sec. The T90 and T50 durations measured by the SGM data are 0.29 +/- 0.05 sec and 0.10+/- 0.03 sec (40-1000 keV), respectively. The ground-processed light curve is available at https://cgbm.calet.jp/cgbm_trigger/ground/1444661491/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University. View this GCN Circular online at https://gcn.nasa.gov/circulars/42321. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...