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GCN Circular 27777

GRB 200521A: CALET Gamma-Ray Burst Monitor detection
2020-05-22T09:52:36Z (4 years ago)
Valentin Pal'shin at AGU <>
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The bright short hard GRB 200521A (AGILE/MCAL and ratemeters detection:
Verrecchia et al., GCN Circ. 27776) triggered the CALET Gamma-ray Burst
Monitor (CGBM) at 12:16:40.803 UTC on 21 May 2020.
The burst signal was seen by all CGBM detectors.
Because of a problem in one of the ground alert processing script, the GCN
notice was not distributed automatically for this event.

The burst light curve shows a bright pulse which starts at T-0.304 sec,
peaks at -0.016 sec and ends at T+0.056 sec. The T90 and T50 durations
measured by the SGM data are 0.240 +- 0.094 sec and 0.104 +- 0.018 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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