TITLE: GCN CIRCULAR NUMBER: 19422 SUBJECT: GRB 160508A: CALET Gamma-Ray Burst Monitor detection DATE: 16/05/11 01:54:08 GMT FROM: Takanori Sakamoto at AGU P. S. Marrocchesi (U of Siena), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence) and the CALET collaboration: The long-duration GRB 160508A (INTEGRAL-ACS trigger #7459; Konus-Wind trigger time on 14:32:38.795 UT) triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 14:32:31.73 on 8 May 2016. The burst signal was seen by all CGBM instruments. The light curve of the SGM shows a single spike starting at T0, peaking at T0+6 sec, and ending at T0+35 sec. A hint of the emission is seen up to T0+~150 sec. The T90 duration measured by the SGM data is 20.0 +- 1.6 sec (40-450 keV). The CGBM data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.