TITLE:   GCN CIRCULAR
NUMBER:  27855
SUBJECT: GRB 200528A: CALET Gamma-Ray Burst Monitor detection
DATE:    20/05/29 12:29:14 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

V. Pal'shin, A. Yoshida, T. Sakamoto, 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),
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long soft GRB 200528A (Swift detection: Ambrosi et al.,
GCN Circ. 27832, Barthelmy et al., GCN Circ. 27839;
Fermi GBM observation: Fletcher and Meegan, GCN Circ. 27841;
https://gcn.gsfc.nasa.gov/other/200528A.gcn3)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 10:27:27.087 UTC
on 28 May 2020. The burst signal was seen by all CGBM detectors.
Because of a problem in one of the ground alert processing script,
the GCN notice was not distributed automatically for this event.

The burst light curve shows a multi-peaked structure which starts at
T-4.5 sec, peaks at T+30.8 sec and ends at T+35.1 sec. The T90 and T50
durations measured by the SGM data are 36.6 +- 3.2 sec and 27.9 +- 4.0 sec
(40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1274696855/

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