A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo, A. Tezuka, S. Matsukawa,
H. Onozawa (AGU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
W. Ishizaki (ICRR), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:
The long GRB 180409A (IPN triangulation: Hurley et al., GCN circ. 22619;
Konus-Wind detection: Frederiks et al., GCN circ. 22621;
Fermi-GBM detection: Bissaldi and Meegan GCN circ. 22626) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 08:18:17.669 UTC on 9 April 2018.
The burst signal was seen by all CGBM detectors.
The burst light curve shows several partially overlapped short pulses
which start at T+3.0 sec, peaks at T+12.3 sec and ends at T+14.9 sec.
The T90 and the T50 durations measured by the SGM data are 10.6 +- 0.7 sec
and 5.9 +- 1.8 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 the Waseda University.