TITLE: GCN CIRCULAR NUMBER: 20171 SUBJECT: GRB 161109A: CALET Gamma-Ray Burst Monitor detection DATE: 16/11/11 23:29:43 GMT FROM: Takanori Sakamoto at AGU I. Takahashi (IPMU), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena) and the CALET collaboration: The long-duration GRB 161109A (Desiante et al., GCN Circ. 20155; Bissaldi et al., GCN Circ. 20156; Konus-Wind trigger time on 6:18:43.284) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 6:18:40.56 on 9 November 2016. The burst signal was seen by all CGBM instruments. The light curve of the SGM shows at least four peaks. The first three peaks are rather weak, and they peak at T+5 sec, T+10 sec and T+15 sec, respectively. The forth peak is the brightest, and it starts at T+20 sec, peaks at T+22 sec and ends at T+32 sec. The T90 duration measured by the SGM data is 24.8 +- 2.3 sec (40-1000 keV). The light curve is available at http://yoshidalab.mydns.jp/cgbm_trigger/flight/1162707406/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.