GCN Circular 30507
Subject
GRB 210725A: CALET Gamma-Ray Burst Monitor detection
Date
2021-07-25T10:59:46Z (3 years ago)
From
Valentin Pal'shin at AGU <val@phys.aoyama.ac.jp>
S. Torii (Waseda U),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka (ICRR), Y. Akaike, K. Kobayashi (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 GRB 210725A (Swift detection: Bernardini et al., GCN Circ. 30501;
https://gcn.gsfc.nasa.gov/other/210725A.gcn3) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 03:47:01.565 UTC on 25 July 2021
(http://cgbm.calet.jp/cgbm_trigger/flight/1311219774/index.html).
The burst signal was seen only by the SGM detector.
The burst light curve shows a single weak pulse which starts at T+1.4 sec,
peaks at T+1.5 sec,and ends at T+6.9 sec. The T90 and T50 durations
measured by the SGM data are 5.0 +- 0.7 sec and 3.0 +- 0.9 sec
(40-1000 keV), respectively.
The ground processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1311219774/
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.