TITLE:   GCN CIRCULAR
NUMBER:  34211
SUBJECT: GRB 230709B: CALET Gamma-Ray Burst Monitor detection
DATE:    23/07/13 06:46:38 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

K. Kobayashi (Waseda 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 (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 230709B (Fermi-GBM Trigger 710614579; 
Fermi-GBM BALROG localization: Biltzinger et al., GCN Circ 34179;
GRBAlpha detection: Dafcikova et al., GCN Circ 34200) was detected
in the ground analysis of the CALET Gamma-ray Burst Monitor (CGBM)
data around 16:56:14.47 UTC on 9 July 2023 (referenced to 
Fermi-GBM Trigger 710614579). 
The burst signal was seen by HXM1 and SGM.

The burst light curve shows a single pulse that starts
at T+0.3 sec, peaks at T+3.5 sec, and ends at T+11.3 sec.
The T90 and T50 durations measured by the SGM data are 
9.9 +/- 0.6 sec and 5.4 +/- 1.1 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1372956935/index.html

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