GCN Circular 46095
Subject
GRB 261029A: CALET Gamma-Ray Burst Monitor detection
Event
Date
2026-10-29T16:07:41Z (2 days ago)
From
Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>
Via
Web form
P. S. Marrocchesi (U of Siena), A. Yoshida, T. Sakamoto, S. Sugita,
Y. Kawakubo (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), N. Cannady (GSFC), M. L. Cherry (LSU),
S. Ricciarini (U of Florence),
and the CALET collaboration:
The CALET Gamma-ray Burst Monitor (CGBM) detected GRB 261029A
at 01:27:33.19 UTC on 29 October 2026 (trigger #1477272361;
https://cgbm.calet.jp/cgbm_trigger/flight/1477272361/index.html).
A CGBM Notice was distributed in near real time.
This event was also reported by Fermi GBM (Fermi GBM team, GCN #46071), SVOM (Goto et al., GCN #46072), Fermi-LAT (Longo et al., GCN #46085), AstroSat CZTI (Salunke et al., GCN #46089).
The burst signal was seen by all CGBM detectors.
The burst light curve shows a multi-peaked structure starting
at T-28.9 s, peaking at T+10.1 s, and ending at T+ 11.9 s.
The T90 and T50 durations measured with the SGM data are 32.2 +/- 1.0 s
and 17.6 +/- 0.3 s in the 40-1000 keV band, respectively.
The ground-processed light curve is available at:
https://cgbm.calet.jp/cgbm_trigger/ground/1477272361/
The CALET data used in this analysis were provided by
the Waseda CALET Operation Center located at Waseda University.