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GCN Circular 22438

GRB 180221B CALET Gamma-Ray Burst Monitor detection
2018-02-23T10:45:37Z (6 years ago)
Takanori Sakamoto at AGU <>
S. Ricciarini (U of Florence), A. Yoshida, T. Sakamoto, V. Pal'shin,
Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (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), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long GRB 180221B (Konus-Wind trigger time on 12:30:00.79) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 12:29:59.616 UTC on
21 February 2018.  The burst signal was seen by all CGBM detectors.

The burst light curve shows a multi-peaked structure which starts at T0,
peaks at T0+16 sec and ends at T0+78 sec.  The T90 and the T50 durations
measured by the SGM data are 66.6 +- 6.8 sec and 21.1 +- 6.3 sec
(40-1000 keV), respectively.

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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