//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32586 SUBJECT: GRB 220926B DATE: 22/09/26 11:24:44 GMT FROM: Diego Gotz at CEA D. Gotz (CEA Saclay), S.Mereghetti (INAF, IASF-Milano), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report: a gamma-ray burst lasting about 20 s has been detected by IBAS in the IBIS/ISGRI data at 10:38:11 UT of 2022 September 26. The refined coordinates (J2000) are: R.A. = 273.9353 deg DEC. = -37.2414 deg with an uncertainty of 1.0 arcmin (90% c.l.). A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32587 SUBJECT: Analysis of long GRB 220926B detected by INTEGRAL DATE: 22/09/26 15:46:31 GMT FROM: Sandro Mereghetti at IASF-Milano/INAF S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report: GRB 220926B detected by IBAS in the IBIS/ISGRI (Gotz et al. GCN 32586) had a peak flux > 2 ph/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range greater than 7e-7 erg/cmq (20 s integration time). Due to telemetry saturation we can provide only lower limits to these quantities. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32781 SUBJECT: GRB 220926B: Detection by GRBAlpha DATE: 22/10/17 13:39:57 GMT FROM: Jakub Ripa at Masaryk University <245487@mail.muni.cz> M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), F. Munz, N. Husarikova, J.-P. Breuer, M. Topinka, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration. The long-duration GRB 220926B (INTEGRAL IBIS/ISGRI detection: Gotz et al., GCN 32586) was detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020). The subthreshold 4.7 sigma detection was confirmed at the peak time 2022-09-26 10:38:21.2 UTC. The light curve obtained by GRBAlpha is temporally consistent with the light curve obtained by INTEGRAL IBIS/ISGRI. The GOES X-ray flux does not show any excess, so we exclude this detection being a solar flare. Therefore, this event is consistent with being a GRB with a duration, as measured by GRBAlpha, of ~8 s. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB220926B_GCN.pdf GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, we are continuously upgrading the on-board data acquisition software stack. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.