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GCN Circular 36046

GRB 240402C: CALET Gamma-Ray Burst Monitor detection
2024-04-07T08:07:31Z (a month ago)
Yuta Kawakubo at Aoyama Gakuin University <>
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Y. Asaoka (ICRR), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 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 240402C (GRBAlpha detection: Dafcikova et al., GCN Circ. 36036;
Glowbug gamma-ray detection: Cheung et al., GCN Circ. 36038) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 05:30:42.49 UTC on 2 April 2024
The burst signal was seen by all CGBM detectors.

The burst light curve shows a double-peaked structure that starts
at T-62.6 sec, peaks at T+1.6 sec, and ends at T+21.1 sec.
The T90 and T50 durations measured by the SGM data are 76.5 +/- 2.6 sec
and 53.5 +/- 1.0 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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