TITLE: GCN CIRCULAR NUMBER: 36764 SUBJECT: GRB 240624B: CALET Gamma-Ray Burst Monitor detection DATE: 24/06/26 03:29:21 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University Y. Akaike (Waseda U), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, 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 240624B (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 36749; GRBAlpha detection: Dafcikova et al., GCN Circ. 36759) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 19:19:42.90 UTC on 24 June 2024 (https://cgbm.calet.jp/cgbm_trigger/flight/1403291510/). The burst signal was seen by all CGBM detectors. The burst light curve shows a main pulse around the trigger time, with weak pulses starting around T + 50 sec. The burst emission starts at T+2.4 sec, peaks at T+3.4 sec, and ends at T+100.4 sec. The T90 and T50 durations measured by the SGM data are 93.6 +/- 1.8 sec and 69.4 +/- 11.7 sec (40-1000 keV), respectively. The ground-processed light curve is available at https://cgbm.calet.jp/cgbm_trigger/ground/1403291510/index.html The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University.