TITLE:   GCN CIRCULAR
NUMBER:  23877
SUBJECT: GRB 190204A: CALET Gamma-Ray Burst Monitor detection
DATE:    19/02/06 14:36:42 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

T. Ito, A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), A. Tezuka, S. Matsukawa, H. Onozawa, 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 190204A (Swift-BAT triggers #887579 and #887580:
Lien et al., GCN Circ. 23852, Sakamoto et al., GCN Circ.23872;
MAXI/GSC detection: Oeda et al., GCN Circ. 23854;
AstroSat CZTI detection: Khanam et al., GCN Circ. 23856;
Konus-Wind observation: Kozlova et al., GCN Circ. 23869)
triggered the CALET Gamma-ray Burst Monitor (CGBM)
at 05:46:05.075 UTC on 4 February 2019.
No real-time CGBM GCN notice was distributed about this trigger
because the real-time communication from the ISS was off (loss of signal).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a single pulse which starts at T-7.7 sec,
peaks at 1.1 sec and ends at T+5.8 sec.
The T90 and T50 durations measured by the SGM data are
11.0 +- 2.0 sec and 2.2 +- 0.5 sec (40-1000 keV), respectively.
The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1233294225/

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