TITLE: GCN CIRCULAR NUMBER: 21282 SUBJECT: GRB 170626B CALET Gamma-Ray Burst Monitor detection DATE: 17/06/29 06:12:38 GMT FROM: Takanori Sakamoto at AGU Y. Asaoka (Waseda U), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU), S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena) and the CALET collaboration: The long-duration GRB 170626B (Liu et al., GCN Circ. 21265; Konus-Wind trigger time on 00:58:02.21 UT) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 00:57:56.28 on 26 June 2017. The burst signal was seen by the all CGBM instruments. The light curve of the SGM shows two overlapping peaks. The emission starts at T+1 sec, peaks at T+2.5 sec (the first peak) and T+5.5 sec (the second peak), and ends at T+10 sec. The T90 duration measured by the SGM data is 5.0 +- 0.4 sec (40-1000 keV). The light curve is available at http://cgbm.calet.jp/cgbm_trigger/flight/1182473374/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.