TITLE:   GCN CIRCULAR
NUMBER:  42156
SUBJECT: GRB 251007A: CALET Gamma-Ray Burst Monitor detection
DATE:    25/10/08 05:38:59 GMT
FROM:    Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>

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/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 251007A (Swift detection: Ambrosi et al., GCN Circ. 42146;
Glowbug gamma-ray detection: Cheung et al., GCN Circ. 42151) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 19:37:48.18 UTC on 7 October 2025
(https://cgbm.calet.jp/cgbm_trigger/flight/1443900615/index.html).
The burst signal was seen by all CGBM detectors. 

The burst light curve shows a multi-peaked structure that starts
at T+3.0 sec, peaks at T+6.3 sec, and ends at T+21.9 sec.
The T90 and T50 durations measured by the SGM data are 15.7 +/- 0.3 sec
and 9.2 +/- 0.3 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

https://cgbm.calet.jp/cgbm_trigger/ground/1443900615/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.