TITLE:   GCN CIRCULAR
NUMBER:  35857
SUBJECT: GRB 240303B: CALET Gamma-Ray Burst Monitor detection
DATE:    24/03/04 02:54:38 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

S. Nakahira (JAXA), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), 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 240303B (Fermi GBM Final Real-time Localization: Fermi GBM team,
GCN Circ. 35850; BALROG localization: Preis et al., GCN Circ 35851; 
INTEGRAL SPI-ACS: Trigger 10612; GECAM: Trigger 301) triggered the 
CALET Gamma-ray Burst Monitor (CGBM) at 12:18:48.35 UTC on 3 March 2024
(http://cgbm.calet.jp/cgbm_trigger/flight/1393503263/).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a multi-peaked structure that starts
at T+2.7 sec, peaks at T+7.2 sec, and ends at T+11.2 sec.
The T90 and T50 durations measured by the SGM data are 5.5 +/- 0.4 sec
and 2.0 +/- 0.1 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1393503263/index.html

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