{
  "eventId": "GRB 230521A",
  "subject": "GRB 230521A: VZLUSAT-2 detection",
  "body": "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.\n\nThe GRB detectors on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/) detected a likely long-duration GRB 230521A. The event was triggered by Konus/Wind at 2023-05-21 18:52:04.019 UT and also observed by INTEGRAL/SPI-ACS at 2023-05-21 18:52:13 UT. The GOES-P X-ray flux does not show any increase at the time of this detection, therefore, it is unlikely to be a solar flare.\n\nThe data acquisition was performed by the GRB detector units no. 0 and no. 1. The detection was confirmed at the peak time 2023-05-21 18:52:10 UTC. The T90 duration is 45 s (46 s) and the significance during T90 reaches 11 sigma (16 sigma) for detector unit no. 0 (no. 1).\n\nThe light curve obtained by VZLUSAT-2 is available here:\nhttps://vzlusat2.konkoly.hu/static/share/GRB230521A_GCN_VZLUSAT2.pdf\n\nAll VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/\nThe 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.\n",
  "circularId": 33906,
  "submitter": "Marianna Dafčíková at Masaryk University <500025@mail.muni.cz>",
  "bibcode": "2023GCN.33906....1D",
  "createdOn": 1685727826250
}