TITLE:   GCN CIRCULAR
NUMBER:  23399
SUBJECT: GRB 181028A: CALET Gamma-Ray Burst Monitor detection
DATE:    18/10/31 11:40:37 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita, Y. Kawakubo,
A. Tezuka, S. Matsukawa, H. Onozawa, T. Ito, H. Morita, Y. Sone (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 181028A (Fermi-LAT detection: Axelsson et al., GCN Circ. 23386;
Fermi-GBM observation: Bissaldi & Meegan, GCN Circ. 23387;
IPN Triangulation: Hurley et al., GCN Circ. 23388;
Konus-Wind observation: Kozlova et al., GCN Circ. 23393)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 14:09:39.546 UTC
on 28 October 2018. The burst signal was seen by all CGBM detectors.

The burst light curve shows a multi-peaked structure
which starts at T+2.6 sec, peaks at T+14.4 sec, and ends at T+32.1 sec.
The T90 and the T50 durations measured by the SGM data are
25.4 +- 5.5 sec and 8.3 +- 0.9 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1224770949/

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