TITLE: GCN CIRCULAR NUMBER: 35811 SUBJECT: GRB 240225B: CALET Gamma-Ray Burst Monitor detection DATE: 24/02/26 22:35:56 GMT FROM: Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu> Y. Kawakubo (LSU), 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 long GRB 240225B (MAXI/GSC detection: Nakajima et al., GCN Circ. 35796; AstroSat CZTI detection: Joshi et al., 35798) was detected in the ground analysis of the CALET Gamma-ray Burst Monitor (CGBM) data around 20:12:08.50 on 25 February 2024 (referenced to the AstroSat detection: GCN Circ. 35798) (http://cgbm.calet.jp/cgbm_trigger/flight/1392926875/index.html). The main episode that AstroSat CZTI detected was seen by all CGBM detectors. Also, a hint of emission that MAXI/GSC detected was seen in the HXM data around T+230 s. The burst light curve of the main episode shows a multi-peaked structure that starts at T-7.6 sec, and ends at T+31.1 sec. The T90 and T50 durations measured by the SGM data are 33.0 +/- 0.9 sec and 17.1 +/- 1.3 sec (40-1000 keV), respectively. The ground-processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1392926875/index.html 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/35811. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...