GCN Circular 35272
Subject
GRB 231204A: CALET Gamma-Ray Burst Monitor detection
Date
2023-12-05T19:10:01Z (5 months ago)
From
Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>
Via
Web form
T. Tamura (Kanagawa U), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu (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 231204A (Fermi GBM Final Real-time Localization:
Fermi GBM team, GCN Circ. 35258; AstroSat CZTI detection:
Waratkar et al., GCN Circ. 35267) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 20:00:00.75 UTC on 4 December 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1385755095/).
The burst signal was seen by only the SGM detector.
The burst light curve shows a weak pulse that starts
at T+3.1 sec, peaks at T+4.1 sec, and ends at T+7.9 sec.
The T90 and T50 durations measured by the SGM data are 4.5 +/- 0.5 sec
and 2.5 +/- 0.1 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1385755095/index.html
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.