TITLE: GCN CIRCULAR NUMBER: 20240 SUBJECT: GRB 161203A: CALET Gamma-Ray Burst Monitor detection DATE: 16/12/07 02:58:46 GMT FROM: Takanori Sakamoto at AGU Y. Asaoka (Waseda U), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 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), P. S. Marrocchesi (U of Siena) and the CALET collaboration: The long-duration GRB 161203A (Konus-Wind trigger time on 18:41:06.318; INTEGRAL-SPI/ACS trigger #7641) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 18:41:07.71 on 3 December 2016. The burst signal was seen by all CGBM instruments. Because of a problem in one of the ground alert processing script, the GCN notice was not distributed automatically for this event. The light curve of the SGM shows at least two overlapping peaks. The first peak starts at T-1 sec, peaks at T+0.5 sec and ends at T+2 sec. The second peak, which is the brightest peak, starts at T+2 sec, peaks at T+3.5 sec and ends at T+6 sec. The T90 duration measured by the SGM data is 5.4 +- 0.8 sec (40-1000 keV). The light curve is available at http://cgbm.calet.jp/cgbm_trigger/flight/1164825510/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.