TITLE:   GCN CIRCULAR
NUMBER:  39725
SUBJECT: GRB 250313A: CALET Gamma-Ray Burst Monitor detection
DATE:    25/03/15 01:55:09 GMT
FROM:    Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>

K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, S. Sugita, 
Y. Kawakubo (AGU), 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 CALET Gamma-ray Burst Monitor (CGBM) was triggered by GRB 250313A 
at 14:34:30.53 UTC on 13 March 2025, which is also detected by Fermi-GBM 
(Fermi-GBM team, GCN #39703), Fermi-LAT (Di Lalla et al., GCN #39711),
AstroSat CZTI (Dasgupta et al., GCN #39714), SVOM/GRM (Wang et al, GCN #39716)
and Konus-Wind (Frederiks et al., GCN #39721). 
(https://cgbm.calet.jp/cgbm_trigger/flight/1425911606/index.html).
The burst signal was seen by all CGBM detectors.  

The burst light curve shows a multi-peaked structure that starts
at T+3.1 sec, peaks at T+11.3 sec, and ends at T+17.4 sec.
The T90 and T50 durations measured by the SGM data are 10.1 +/- 0.5 sec
and 4.8 +/- 0.3 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

https://cgbm.calet.jp/cgbm_trigger/ground/1425911606/

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