GCN Circular 19671

I. Takahashi (IPMU), 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)
P. S. Marrocchesi (U of Siena) and the CALET collaboration:

The long-duration GRB 160628A (Fermi-GBM trigger #488814821;
Konus-Wind trigger time on 13:53:41.910) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 13:53:37.9 on 28 June 2016.  The burst signal
was only seen by the SGM instrument.

The light curve of the SGM shows a double peak structure starting at T+0.1 sec
and ending at T+6 sec.  The peak times of the spikes are T+1 sec and T+3.5 sec.
The T90 duration measured by the SGM data is 5.1 +- 0.9 sec (40-230 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1151157163/

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