TITLE:   GCN CIRCULAR
NUMBER:  25246
SUBJECT: GRB 190731A: CALET Gamma-Ray Burst Monitor detection
DATE:    19/08/01 10:06:20 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

Y. Asaoka (Waseda U),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (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 long bright GRB 190731A (Fermi GBM Final Real-time Localization: Fermi
GBM Team, GCN Circ. 25240; Fermi-LAT detection: Ohno et al., GCN Circ.
25244) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 22:38:18.315
UTC on 31 July 2019. The burst signal was seen by all CGBM detectors.

The burst light curve shows a single multi-peaked emission episode which
starts at T+3.1 sec, peaks at T+4.4 sec and ends at T+26.0 sec. The T90
and T50 durations measured by the SGM data are 14.6 +- 1.8 sec and
5.0 +- 0.5 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1248647800/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.