TITLE:   GCN CIRCULAR
NUMBER:  33473
SUBJECT: VZLUSAT-2 detection of SGR 1806-20
DATE:    23/03/13 21:28:20 GMT
FROM:    Marianna Dafcikova at Masaryk University  <500025@mail.muni.cz>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory),  N.
Werner  (Masaryk U.), M. Ohno (Hiroshima U.),  L. Meszaros, B. Csak
(Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka,
F. Hroch, N. Husarikova, J.-P. Breuer (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.


The GRB detector on board the VZLUSAT-2 3U CubeSat (
https://www.vzlusat2.cz/en/) detected an outburst from the SGR 1806-20
(Swift/BAT detection: GCN 33451; Konus/Wind detection at  2023-03-10
21:00:32.718 UT; INTEGRAL/SPI-ACS detection at 2023-03-10 21:00:35 UT).

The data acquisition was performed by GRB detector units no. 0 and no. 1.
The detection was confirmed at the peak time 2023-03-10 21:00:34 UTC. The
temporal resolution of the observation was 1 s and both light curves show a
spike within one bin in the 40-110 keV band. The detection significance
reached 8.6 sigma (19.4 sigma) for detector unit no. 0 (no. 1).

The light curve obtained by VZLUSAT-2 is available here:

https://vzlusat2.konkoly.hu/static/share/SGR1806-20_GCN_VZLUSAT2.pdf

All VZLUSAT-2 detections are listed at:
https://monoceros.physics.muni.cz/hea/VZLUSAT-2/

The GRB detectors on VZLUSAT-2 are a demonstration payload for a future
CubeSat 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.