TITLE: GCN CIRCULAR NUMBER: 32139 SUBJECT: GRB 220527A: CALET Gamma-Ray Burst Monitor detection DATE: 22/05/28 03:10:53 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, S. Sugita (AGU), Y. Kawakubo (LSU), S. Nakahira (RIKEN), 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 bright long GRB 220527A (AGILE detection: Ursi et al., GCN Circ. 32129; Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 32130; Fermi-LAT detection: Bissaldi et al., GCN Circ. 32131) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 09:17:14.518 UTC on 27 May 2022 (http://cgbm.calet.jp/cgbm_trigger/flight/1337678064/index.html). The burst signal was seen by all CGBM detectors. The burst light curve shows a multi-peaked structure which starts at T+0.5 sec, peaks at T+9.1 sec, and ends at T+21.9 sec. The T90 and T50 durations measured by the SGM data are 10.2 +/- 1.0 sec and 3.9 +/- 0.1 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1337678064/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.