GRB 241120A: CALET Gamma-Ray Burst Monitor detection

The long GRB 241120A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 38279; a long GRB detected by INTEGRAL: Gotz et al., GCN Circ. 38280; Fermi GBM Observation, Hamburg et al., GCN Circ. 38285) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 05:54:00.493 UTC on 20 November 2024 (https://cgbm.calet.jp/cgbm_trigger/flight/1416117245/index.html). 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 single emission episode that starts at T-3.0 sec, peaks at T+0.1 sec, and ends at T+0.8 sec. The T90 and T50 durations measured by the SGM data are 2.9 ± 0.5 sec and 0.8 ± 0.3 sec (40-1000 keV), respectively. The ground-processed light curve is available at https://cgbm.calet.jp/cgbm_trigger/ground/1416117245/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University.