[vsnet-grb-info 28181] GRB 210619B: CALET Gamma-Ray Burst Monitor detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30284
SUBJECT: GRB 210619B: CALET Gamma-Ray Burst Monitor detection
DATE:    21/06/21 10:39:15 GMT
FROM:    Valentin Pal'shin at AGU  <val at phys.aoyama.ac.jp>

Y. Kawakubo (LSU),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR),
S. Torii, Y. Akaike, K. Kobayashi (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 bright GRB 210619B (Swift detection: D'Avanzo et al.,
GCN Circ. 30261, Lien et al., GCN Circ. 30282; GECAM detection: Zhao et al.,
GCN Circ. 30264; Fermi-LAT detection: Axelsson et al., GCN Circ. 30270;
Konus-Wind detection: Svinkin et al., GCN Circ. 30276;
Fermi GBM detection: Poolakkil and Meegan, GCN Circ. 30279;
SRG/ART-XC detection: Levin et al., GCN Circ. 30283;
https://gcn.gsfc.nasa.gov/other/210619B.gcn3) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 23:59:21.940 UTC on 19 June 2021
(http://cgbm.calet.jp/cgbm_trigger/flight/1308182178/index.html).
The burst signal was seen by all CGBM detectors.

The burst light curve shows the bright initial pulse which starts
at T+3.5 sec and peaks at T+4.3 sec, followed by several weaker pulses
which end at T+85.4 sec. The T90 and T50 durations measured by the SGM data
are 49.9 +- 1.8 sec and 14.4 +- 0.6 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1308182178/

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