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GCN Circular 35137

GRB 231118B: CALET Gamma-Ray Burst Monitor detection
2023-11-20T15:07:18Z (15 days ago)
Yuta Kawakubo at Louisiana State University <>
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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 231118B (Fermi GBM Final Real-time Localization: 
Fermi GBM team, GCN Circ. 35111; BALROG localization: Preis 
et al., GCN Circ 35112; Fermi GBM observation: de Barra et al.,
GCN Circ 35132) triggered the CALET Gamma-ray Burst 
Monitor (CGBM) at 22:34:15.15 UTC on 18 November 2023
The burst signal was seen by HXM1 and SGM detectors.  No real-time 
CGBM GCN notice was distributed about this trigger because
the real-time communication from the ISS was off (loss of signal).

The burst light curve shows a single pulse that starts
at T-0.7 sec, peaks at T+2.8 sec, and ends at T+6.5 sec.
The T90 and T50 durations measured by the SGM data are 5.6 +/- 0.3 sec
and 2.4 +/- 0.1 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

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