TITLE: GCN CIRCULAR NUMBER: 26809 SUBJECT: GRB 200115A: CALET Gamma-Ray Burst Monitor detection DATE: 20/01/18 02:18:13 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. 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: The very long GRB 200115A detected by Swift (Cenko et al., GCN Circ. 26771, Laha et al., GCN Circ.26780; https://gcn.gsfc.nasa.gov/other/200115A.gcn3) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 11:52:05.424 UTC on 15 January 2020. The burst signal was seen by all CGBM detectors. Because of a problem in one of the ground alert processing script, the GCN notice was not distributed automatically for this event. The burst light curve shows a multi-peaked structure which starts at T-206 sec, peaks at T-3 sec and ends at T+221 sec. The T90 and T50 durations measured by the SGM data are 347 +- 46 sec and 104 +- 29 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1263124124/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.