TITLE: GCN CIRCULAR NUMBER: 25615 SUBJECT: GRB 190831B: CALET Gamma-Ray Burst Monitor detection of a short burst DATE: 19/09/02 14:28:43 GMT FROM: Valentin Pal'shin at AGU T. Tamura (Kanagawa U), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: At 06:30:28.620 UTC on 31 August 2019, the CALET Gamma-ray Burst Monitor (CGBM) triggered on short GRB 190831B. The burst signal was mainly seen by the SGM detector. No real-time CGBM GCN notice was distributed about this trigger because the real-time communication from the ISS was off (loss of signal). This short burst also triggered INTEGRAL SPI-ACS (trigger #8366). The burst light curve shows a single pulse which starts at T-0.6 sec, peaks at T-0.4 sec and ends at T+0.2 sec. The T90 and T50 durations measured by the SGM data are 0.7 +- 0.2 sec and 0.4 +- 0.2 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1251268076/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.