TITLE:   GCN CIRCULAR
NUMBER:  34679
SUBJECT: GRB 230908A: CALET Gamma-Ray Burst Monitor detection
DATE:    23/09/13 04:14:01 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

N. Cannady (GSFC/UMBC), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 230908A (AstroSat CZTI detection: Navaneeth et al.,
GCN Circ. 34645; GRBAlpha detection: Dafcikova et al., GCN
Circ. 34647; Swift/BAT-GUANO detection: Tohuvavohu et al.,
GCN Circ. 34661) triggered the CALET Gamma-ray Burst Monitor 
(CGBM) at 16:41:17.84 UTC on 8 September 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1378226327/index.html).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a single pulse that starts
at T+2.1 sec, peaks at T+4.1 sec, and ends at T+9.6 sec.
The T90 and T50 durations measured by the SGM data are 6.2 +/- 0.6 sec
and 2.7 +/- 0.2 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1378226327/

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