TITLE:   GCN CIRCULAR
NUMBER:  22267
SUBJECT: GRB 171210A CALET Gamma-Ray Burst Monitor detection
DATE:    17/12/23 00:34:09 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Matsukawa, A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo, M. Moriyama,
Y. Yamada, A. Tezuka (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
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), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171210A (Bissaldi et al., GCN circ. 22228; Poolakkil et al.,
GCN circ. 22233; Kozlova et al., GCN circ. 22244) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 11:49:17.22 on 10 December 2017.  The burst signal was seen
by all the instruments.  Because of a problem in one of the ground alert processing
scripts, the GCN notice was not distributed automatically for this event.

The light curve of the SGM shows a single FRED-like pulse. The emission starts
at T-5 sec, peaks at T+5 sec and ends at T+50 sec.  The T90 duration measured
by the SGM data is 47.4 +- 2.5 sec (40-1000 keV).

The emission is seen up to ~T+180 s in the low energy ranges of the HXM data.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1196941607/

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