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GCN Circular 22304

GRB 171229A CALET Gamma-Ray Burst Monitor detection
2018-01-06T12:56:48Z (6 years ago)
Takanori Sakamoto at AGU <>
S. Nakahira (RIKEN), A. Yoshida, T. Sakamoto, V. Pal'shin,Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
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 171229A (Konus-Wind trigger time on 09:59:28.212)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 09:59:37.40 on
29 December 2017.  This GRB is also clearly seen by the publicly available
INTEGRAL SPI-ACS light curve.  The burst signal was seen only by the SGM

The light curve of the SGM shows a single pulse followed by a weak extended
emission.  The emission starts at T-10 sec, peaks at T0 and ends at T+67 sec.
The T90 duration measured by the SGM data is 70.8 +- 6.9 sec (40-1000 keV).
The T50 duration measured by the SGM data is 38.1 +- 17.7 sec (40-1000 keV).

The ground processed light curve is available at

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