TITLE:   GCN CIRCULAR
NUMBER:  25981
SUBJECT: GRB 191004A: CALET Gamma-Ray Burst Monitor detection
DATE:    19/10/08 12:30:46 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

K. Yamaoka (Nagoya U),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The soft GRB 191004A (Swift-BAT detection: Cenko et al., GCN Circ. 25945,
Sakamoto et al., GCN Circ. 25953; Konus-Wind observation: Svinkin et al.,
GCN Circ. 25973) triggered the CALET Gamma-ray Burst Monitor (CGBM) at
18:07:05.528 UTC on 4 October 2019. The burst signal was seen by all CGBM
detectors.
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 light curve shows two pulses which start at T-2.7 sec and end
at T+0.0 sec. The T90 and T50 durations measured by the SGM data are
2.6 +- 0.3 sec and 1.9 +- 1.4 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1254247608/

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