GCN Circular 31965

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 (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 220423A (AGILE/MCAL detection: Ursi et al., GCN 
Circ. 31938
Not found
 
 
, Happy Birthday to AGILE!; Swift/BAT detection: Raman et 
al., GCN Circ. 31943
Not found
 
 
; CALET/CGMB detection: trig. #1334758343; 
INTEGRAL/SPI-ACS detection: trig. #9870; KONUS-Wind detection: trig. 
time 2022-04-23 14:14:07.818 UT) was detected by both GRB detector units 
on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).

The data acquisition was performed by GRB detector units no. 0 and no. 
1. The 28 sigma detection significance was confirmed at each detector at 
2022-04-23 14:14:14 UTC. The GRB has the T90 duration of 37 s.

The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB220423A_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.