TITLE:   GCN CIRCULAR
NUMBER:  35623
SUBJECT: GRB 240122B: CALET Gamma-Ray Burst Monitor detection
DATE:    24/01/24 20:04:13 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

S. Ricciarini (U of Florence), 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),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), 
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 240122B (Glowbug gamma-ray detection: 
Cheung et al., GCN Circ. 35606) triggered the CALET 
Gamma-ray Burst Monitor (CGBM) at 19:16:26.96 UTC 
on 22 January 2024
(http://cgbm.calet.jp/cgbm_trigger/flight/1389985993/).
The burst signal was seen by HXM2 and SGM.

The burst light curve shows a double-peaked structure that starts
at T-57.2 sec, peaks at T+9.0 sec, and ends at T+17.1 sec.
The T90 and T50 durations measured by the SGM data are 
69.2 +/- 1.9 sec and 32.2 +/- 19.7 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1389985993/index.html

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