{
  "bibcode": "2022GCN.32685....1R",
  "body": "J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk \nU.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly \nObservatory), M. Dafcikova, F. Munz, N. Husarikova, J.-P. Breuer, M. \nTopinka, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,�� A. Povalac (Brno \nU. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. \nLaszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky \n(Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos \nU.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida \n(ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto \n(Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. \nHirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), \nK. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),�� T. Mizuno \n(Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. \nTakatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama \n(Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) \n-- the GRBAlpha collaboration.\n\nThe extraordinarily bright long-duration GRB 221009A (Swift/BAT \ndetection: Kennea et al., GCN 32635; Fermi-GBM detection: Veres et al., \nGCN 32636; Fermi-LAT detection: Pillera et al., GCN 32658; INTEGRAL \nSPI/ACS detection: Gotz et al., GCN 32660; Konus-Wind detection: \nFrederiks et al., GCN 32668; IPN triangulation: Svinkin et al., GCN \n32641; LHAASO detection: Huang et al., GCN 32677) at a redshift of z = \n0.151 (de Ugarte Postigo et al., GCN 32648) was detected by the GRBAlpha \n1U CubeSat (Pal et al. Proc. SPIE 2020).\n\nThe GRB did not saturate our detector and the peak count rate reached \n~22 000 count/s in the ~70-890 keV energy band (for a 50 cm^2 detector) \nat 2022-10-09 13:20:52 UTC. The duration of the GRB was >250s. GRBAlpha \nwas flying above the northern polar region with elevated background \nlevels. The end part of the GRB was recorded while passing the outer Van \nAllen radiation belt.\n\nThe light curve obtained by GRBAlpha is available here:\nhttps://grbalpha.konkoly.hu/static/share/GRB221009A_GCN_GRBAlpha.pdf\n\nGRBAlpha, launched on 2021 March 22, is a demonstration mission for a \nfuture CubeSat constellation (Werner et al. Proc. SPIE 2018). Its \ndetector consists of a 75 x 75 x 5 mm^3 CsI(Tl) scintillator read out by \na SiPM array, covering the energy range from ~50 keV to ~1000 keV. To \nincrease the duty cycle and the downlink rate, we are continuously \nupgrading the on-board data acquisition software stack. The ground \nsegment is also supported by the radio amateur community and it takes \nadvantage of the SatNOGS network for increased data downlink volume.",
  "circularId": 32685,
  "createdOn": 1665494678000,
  "email": "245487@mail.muni.cz",
  "subject": "GRB 221009A: Detection by GRBAlpha",
  "submitter": "Jakub Ripa at Masaryk University  <245487@mail.muni.cz>",
  "eventId": "GRB 221009A"
}