TITLE:   GCN CIRCULAR
NUMBER:  19730
SUBJECT: GRB 160721A: CALET Gamma-Ray Burst Monitor detection
DATE:    16/07/24 12:03:56 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Torii (Waseda U), 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 (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena) and the CALET collaboration:

The long-duration GRB 160721A (Fermi-GBM trigger #490821662;
INTEGRAL-ACS trigger #7516) triggered the CALET Gamma-ray Burst
Monitor (CGBM) at 19:20:58.54 on 21 July 2016.  The burst signal was
seen by all CGBM instruments.

The light curve of the SGM shows two short spikes with a broad emission.
The short spikes are peaked at T+0 sec and T+1.8 sec with the durations
less than a second.  The underline broad emission ends around T+10 sec.
The T90 duration measured by the SGM data is 8.6 +- 0.6 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1153163965/

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