GCN Circular 40932
Subject
GRB 250702A: CALET Gamma-Ray Burst Monitor detection
Event
Date
2025-07-04T04:55:55Z (25 days ago)
From
Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>
Via
Web form
K. Kobayashi (Waseda U), A. Yoshida, T. Sakamoto, S. Sugita,
Y. Kawakubo (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, (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 250702A (Fermi GBM Final Real-time Localization: Fermi GBM team,
GCN Circ. 40881; BALROG localization: Preis et al., GCN Circ 40882; Fermi GBM
Detection: Malacaria et al., GCN Circ. 40887; GECAM-B detection: Wang et al.,
GCN Circ. 40992) triggered the CALET Gamma-ray Burst Monitor (CGBM) at
09:54:05.81 UTC on 2 July 2025
(https://cgbm.calet.jp/cgbm_trigger/flight/1435484973/index.html).
The burst signal was seen by all CGBM detectors.
The burst light curve shows a single pulse that starts
at T+1.5 sec, peaks at T+6.2 sec, and ends at T+14.4 sec.
The T90 and T50 durations measured by the SGM data are 10.5 +/- 0.6 sec
and 3.9 +/- 0.3 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
https://cgbm.calet.jp/cgbm_trigger/ground/1435484973
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.