TITLE:   GCN CIRCULAR
NUMBER:  26972
SUBJECT: GRB 200131A: CALET Gamma-Ray Burst Monitor detection
DATE:    20/02/03 07:07:14 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

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

The bright GRB 200131A detected by Swift (Sbarufatti et al.,
GCN Circ. 26953, Sakamoto et al., GCN Circ. 26967;
https://gcn.gsfc.nasa.gov/other/200131A.gcn3)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 22:41:11.299 UTC
on 31 January 2020. The burst signal was seen by all CGBM detectors.

The burst light curve shows a multi-peaked structure which starts
at T+3.3 sec, peaks at T+3.8 sec and ends at T+6.4 sec.
The T90 and T50 durations measured by the SGM data are 2.2 +- 0.1 sec
and 1.4 +- 0.1 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1264545439/

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