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GCN Circular 25865

GRB 190928A: CALET Gamma-Ray Burst Monitor detection
2019-09-30T08:17:04Z (5 years ago)
Valentin Pal'shin at AGU <>
V. Pal'shin, A. Yoshida, T. Sakamoto, 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 long bright GRB 190928A (AGILE/MCAL detection: Ursi et al., GCN Circ.
25859; IPN triangulation: Hurley et al., GCN Circ. 25864) triggered the
CALET Gamma-ray Burst Monitor (CGBM) at 13:12:11.187 UTC on 28 September
2019. The burst signal was seen by all CGBM detectors.

The burst light curve shows two multi-peaked pulses separated by a period
of low-level emission. The first pulse starts at T+2.6 sec, peaks at
T+4.8 sec and ends at T+8.1 sec, the second, much brighter, pulse starts at
T+76.4 sec, peaks at T+106.1 sec and ends at T+175.5 sec.
The T90 and T50 durations measured by the SGM data are 106.6 +- 49.1 sec and
6.9 +- 0.4 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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