GRB 221020A: Detection by GRBAlpha

The long-duration GRB 221020A (Fermi-GBM detection: Fermi GBM Team, GCN Circ. 32806) was detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020). The 11.3 sigma detection was confirmed at the peak time 2022-10-20 05:23:59.8 UTC. The GRB has a T90 duration of 15 s. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB221020A_GCN_GRBAlpha.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.