TITLE:   GCN CIRCULAR
NUMBER:  38569
SUBJECT: GRB 241209D: CALET Gamma-Ray Burst Monitor detection
DATE:    24/12/14 09:21:25 GMT
FROM:    Yuta Kawakubo at Aoyama Gakuin University <kawakubo@phys.aoyama.ac.jp>

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), 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 241209D (Fermi GBM Final Real-time Localization: 
Fermi GBM team, GCN Circ 38488; Swift detection of a burst: 
Parsotan et al., GCN Circ 38489; Fermi GBM Observation: Malacaria
et al., GCN Circ 38507; AstroSat CZTI detection: Tembhurnikar et al.,
GCN Circ 38518; Konus-Wind detection: Ridnaia et al., GCN Circ 
38526) triggered the CALET Gamma-ray Burst Monitor (CGBM) at
10:59:46.760 UTC on 9 December 2024
(https://cgbm.calet.jp/cgbm_trigger/flight/1417777157/index.html).
The burst signal was seen by only the SGM detector.  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 single pulse that starts at T-4.0 sec, 
peaks at T+0.6 sec, and ends at T+6.7 sec. The T90 and T50 durations
measured by the SGM data are 9.2 +/- 0.7 sec and 4.6 +/- 0.4 
sec (40-1000 keV), respectively.

The ground-processed light curve is available at

https://cgbm.calet.jp/cgbm_trigger/ground/1417777157/

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