TITLE:   GCN CIRCULAR
NUMBER:  33563
SUBJECT: GRB 230402A: CALET Gamma-Ray Burst Monitor detection
DATE:    23/04/04 15:29:58 GMT
FROM:    Yuta Kawakubo at Louisiana State U./CALET  <kawakubo1@lsu.edu>

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

The long GRB 230402A (Fermi GBM Final Real-time Localization: 
Fermi GBM team, GCN Circ. 33553; AGILE detection: Casentini et al.,
GCN Circ 33555; AstroSat CZTI detection: Navaneeth et al., GCN Circ. 
33562) triggered the CALET Gamma-ray Burst Monitor (CGBM)at 
07:32:38.72 UTC on 2 April 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1364455761/).
The burst signal was seen by only the SGM detector.

The burst light curve shows a single pulse that starts
at T-3.2 sec and ends at T+4.8 sec.
The T90 and T50 durations measured by the SGM data are 7.0 +/- 1.0 sec
and 4.0 +/- 1.0 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1364455761/

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