GCN Circular 22816

K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, V. Pal'shin,
Y. Kawakubo, A. Tezuka, S. Matsukawa, H. Onozawa, T. Ito,
H. Morita, Y. Sone (AGU), 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 180618B (INTEGRAL SPI-ACS trigger #8079;
Konus-Wind trigger time on 22:40:26.066)
triggered the CALET Gamma-ray Burst Monitor (CGBM)
at 22:40:18.199 UTC on 18 June 2018.  The burst signal
was clearly seen by the SGM instrument.  There is a hint
of the emission seen by the HXM instrument.

The burst light curve shows a single FRED-like pulse which starts
at T-3.8 sec, peaks at T-1.5 sec and ends at T+15.4 sec.
The T90 and the T50 durations measured by the SGM data are
17 +- 4 sec and 5.3 +- 0.5 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1213396756

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