TITLE: GCN CIRCULAR NUMBER: 32180 SUBJECT: GRB 220606C: CALET Gamma-Ray Burst Monitor detection DATE: 22/06/08 06:20:55 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET S. Nakahira (RIKEN), A. Yoshida, T. Sakamoto, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), 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 220606C triggered the CALET Gamma-ray Burst Monitor (CGBM) at 13:35:14.394 UTC on 6 June 2022 (http://cgbm.calet.jp/cgbm_trigger/flight/1338557524/index.html). The burst signal was seen by only SGM. The burst light curve shows a single pulse which starts at T+3.1 sec, peaks at T+4.1 sec, and ends at T+47.4 sec. The T90 and T50 durations measured by the SGM data are 30.4 +/- 7.8 sec and 6.9 +/- 0.6 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1338557524/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.