TITLE: GCN CIRCULAR NUMBER: 18872 SUBJECT: GRB 160106A: CALET Gamma-Ray Burst Monitor detection DATE: 16/01/16 04:52:16 GMT FROM: Takanori Sakamoto at AGU K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, K. Senuma, M. Moriyama, Y. Yamada (AGU), S. Nakahira (JAXA), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), M. L. Cherry (LSU), S. Ricciarini (U of Florence) P. S. Marrocchesi (U of Siena) and the CALET collaboration: The long-duration GRB 160106A (Fermi-GBM trigger #473813134; Konus-Wind triggered on 22:45:37.257 UT) triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 22:45:34.70 UT on 6 January 2016. The clear burst signal was detected by all instruments. The low energy light curve of the HXM shows two main episodes. The first structure, which is composed of at least two spiky features, starts at T0, peaks at T0+2 sec (first spike) and at T0+8 sec (second spike) and apparently accompanied by an other hump, and then ends at T0+20 sec. The second structure starts at T0+30 sec, peaks at T0+33 sec and ends at T0+45 sec. The second structure looks invisible above 300 keV. The T90 duration measured by the SGM data is 39.3 s +/- 0.9 sec (40-1000 keV). The CGBM data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.