TITLE:   GCN CIRCULAR
NUMBER:  37691
SUBJECT: GRB 240930B: CALET Gamma-Ray Burst Monitor detection
DATE:    24/10/03 11:34:40 GMT
FROM:    Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>

Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii,
Y. Akaike, K. Kobayashi (Waseda U), 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 240930B (Fermi GBM Final Real-time Localization: Fermi GBM team, 
GCN Circ. 37640; EP-WXT detection of a fast X-ray transient: Tian et al.,
GCN Circ. 37648; Swift/BAT-GUANO localization skymap of a burst: DeLaunay et al.,
GCN Circ. 37654; GRBAlpha detection, Dafcikova et al., GCN Circ. 37658; 
Fermi GBM Observation: Smith et al., GCN Circ. 37660)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 17:18:02.638 UTC 
on 30 September 2024 
(https://cgbm.calet.jp/cgbm_trigger/flight/1411751821/).
The burst signal was seen by all CGBM detectors.  Because of a problem with the ground 
alert processing script, the GCN notice was not distributed automatically for this event.

The burst light curve shows a multi-peaked structure that starts
at T-1.5 sec, peaks at T+3.5 sec, and ends at T+74.0 sec.
The T90 and T50 durations measured by the SGM data are 67.2 s +/- 3.1 sec
and 34.7 s +/- 0.4 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

https://cgbm.calet.jp/cgbm_trigger/ground/1411751821/

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