TITLE: GCN CIRCULAR NUMBER: 22358 SUBJECT: GRB 180112A CALET Gamma-Ray Burst Monitor detection DATE: 18/01/17 05:40:23 GMT FROM: Takanori Sakamoto at AGU S. Ozawa (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, 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 180112A (INTEGRAL SPI-ACS trigger #7990; Konus-Wind trigger time on 16:29:11.736) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 16:29:08.39 on 12 January 2018. The burst signal was seen by the all CGBM instruments. The light curve of the SGM shows three isolated episodes. The first weak episode peaks around T+2 sec with the duration of 4 sec. The second episode has two overlapping pulses, and its emission starts at T+80 sec, peaks at T+100 sec and ends at T+110 sec. The third brightest episode has a single pulse, and its emission starts at T+200 sec, peaks at T+230 sec and ends at T+250 sec. The T90 and the T50 durations measured by the SGM data are 155 +- 80 sec and 134.5 +- 1.2 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1199809543 The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.