{
  "bibcode": "2021GCN.30624....1R",
  "body": "J. Ripa (Masaryk U.), M. Ohno (Eotvos U./Hiroshima U.), H. Takahashi\n(Hiroshima U.),\nA. Pal, L. Meszaros, B. Csak (Konkoly Observatory), N. Werner, M. Topinka,\nF. Munz,\nF. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of\nTechnology),\nJ. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda\n(Needronix s.r.o),\nM. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi\n(Wigner Research Center/Eotvos U.),\nYuusuke Uchida, Helen Poon, H. Matake, N. Uchida (Hiroshima U.), T. Enoto\n(Kyoto U.), Zs. Frei (Eotvos U.),\nY. Fukazawa, K. Hirose (Hiroshima U.); S. Hisadomi (Nagoya U.), Y. Ichinohe\n(Rikkyo U.),\nL. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa\n(Nagoya U.),\nH. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.) -- the GRBAlpha\ncollaboration.\n\nThe long duration GRB 210807A (Swift-BAT detection; Lien et al. GCN Circ.\n 30600)\nwas detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020).\nThis is the first time that a GRB was observed by a 1U CubeSat dedicated to\ngamma-ray burst observations.\n\nThe data acquisition started at 10:05:14 UT and the tail part of the prompt\nemission, which  consists of multiple peaks,\nwas observed with a duration of about 80 sec. The 7.3 sigma detection\nsignificance was confirmed at around 10:06:00 UT.\n\nThe light curve obtained by GRBAlpha is available here:\nhttps://grbalpha.konkoly.hu/static/share/GRB210807A.pdf\n\nGRBAlpha is a demonstration mission for a future CubeSats constellation\n(Werner et al. Proc. SPIE 2018).\nThe detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator\nread out by a SiPM array,\ncovering the energy range from ~50 keV to ~1000 keV.\nGRBAlpha was launched on 2021 March 22 from Baikonur. After its\ncommissioning phase,\nthe scientific observations are now under way. To increase the duty cycle\nand the downlink rate,\nthe upgrade of the on-board data acquisition software stack is in progress.\nThe ground segment is also supported by the radio amateur community and it\ntakes advantage\nof the SatNOGS network for increased data downlink volume.",
  "circularId": 30624,
  "createdOn": 1628606242000,
  "email": "ohno@astro.hiroshima-u.ac.jp",
  "subject": "GRB 210807A: Detection by GRBAlpha",
  "submitter": "Masanori Ohno at Hiroshima University  <ohno@astro.hiroshima-u.ac.jp>",
  "eventId": "GRB 210807A"
}