Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 30284

GRB 210619B: CALET Gamma-Ray Burst Monitor detection
2021-06-21T10:39:15Z (3 years ago)
Valentin Pal'shin at AGU <>
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; triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 23:59:21.940 UTC on 19 June 2021
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

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.
Looking for U.S. government information and services? Visit