GCN Circular 32463

J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), M. Ohno (Hiroshima U.),
 N. Werner  (Masaryk U.),  L. Meszaros (Konkoly Observatory), H. Takahashi
(Hiroshima U.), B. Csak (Konkoly Observatory), M. Topinka, F. Munz, F.
Hroch, M. Dafcikova, J.-P. Breuer, N. Husarikova (Masaryk U.), J. Hudec, J.
Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G.
Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T.
Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake
(Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L.
Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya
U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V.
Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU)  -- the
VZLUSAT-2/GRB payload collaboration.

A long-duration GRB 220719A (triggered by KONUS-Wind at 2022/07/19
19:09:46.939 UT; also detected by INTEGRAL/SPI-ACS with peak at 2022/07/19
19:09:45.0 UT - private communication with Dmitry Svinkin) was detected by
a GRB detector on board of the VZLUSAT-2 3U CubeSat (
https://www.vzlusat2.cz/en/).

The data acquisition was performed by the GRB detector unit no. 1. The 6.2
sigma detection was confirmed at the peak time 2022-07-19 19:09:43.5 UTC.
The GRB has the T90 duration of 7 s.

The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB220719A_GCN_VZLUSAT2.pdf

GRB detectors on VZLUSAT-2 are a demonstration payload for a future
CubeSats constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of
VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x
75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy
range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13
from Cape Canaveral.

We acknowledge the help of Dmitry Svinkin (Ioffe Institute) and Anastasia
Tsvetkova (Ioffe Institute) with the confirmation that this event was a
long GRB and also detected by INTEGRAL/SPI-ACS.