TITLE:   GCN CIRCULAR
NUMBER:  27572
SUBJECT: GRB 200412B: CALET Gamma-Ray Burst Monitor detection
DATE:    20/04/14 08:20:52 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

T. Tamura (Kanagawa U),
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 (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 bright GRB 200412B (BALROG localization: Burgess et al.,
GCN Circ. 27548; Fermi-LAT detection: Longo et al., GCN Circ. 27557;
Fermi GBM detection: Mailyan and Hamburg, GCN Circ. 27558;
https://gcn.gsfc.nasa.gov/other/200412B.gcn3)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 09:08:43.975 UTC
on 12 April 2020. The burst signal was seen by all CGBM detectors.

The burst light curve shows a multi-peaked structure which starts
at T-0.3 sec, peaks at T+6.2 sec and ends at T+13.1 sec. The T90 and T50
durations measured by the SGM data are 6.1 +- 0.5 sec and 1.8 +- 0.1 sec
(40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1270717362/

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