GRB 221122A: Detection by GRBAlpha

The short-duration GRB 221122A (GECAM-B detection at 2022-11-22 02:43:26.65 UT, trigger no. 77) was detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020). The subthreshold detection was confirmed at the peak time 2022-11-22 02:43:26 UTC. The GRB has a T90 duration of 2 s and the overall significance during T90 reaches 4.3. The duration and the detection time of the event are consistent with the GRB reported by the GECAM-B instrument. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB221122A_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.