TITLE: GCN CIRCULAR NUMBER: 33452 SUBJECT: GRB 230308A: CALET Gamma-Ray Burst Monitor detection DATE: 23/03/11 10:29:09 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), 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 230308A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 33420; BALROG localization: Kunzweiler et al., GCN Circ 33421; AGILE/MCAL detection: Casentini et al., GCN Circ 33435; Fermi GBM detection: Malacaria et al., GCN Circ 33440) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 13:32:27.34 UTC on 8 March 2023 (http://cgbm.calet.jp/cgbm_trigger/flight/1362317395/index.html). The burst signal was seen by all CGBM detectors. The burst light curve shows a multi-peaked structure that starts at T+0.04 sec, peaks at T+0.21 sec, and ends at T+0.37 sec. The T90 and T50 durations measured by the SGM data are 0.29 +/- 0.04 sec and 0.17 +/- 0.04 sec (40-1000 keV), respectively. The ground-processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1362317395/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University.