TITLE: GCN CIRCULAR NUMBER: 43710 SUBJECT: GRID detection of GRB 250207B DATE: 26/02/12 08:33:36 GMT FROM: GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn> Ming Zeng, Chenyu Wang, Longhao Li, Zirui Yang report on behalf of the GRID Collaboration: GRID reports the detection of GRB 250207B, which was also observed by Fermi-GBM (Fermi GBM team, GCN 43629; Sonawane & Bala, GCN 43634), GECAM-B (Zao et al., GCN 43644), and AstroSat CZTI (Goyal et al., GCN 43680). The event triggered GRID-09B, GRID-10B, and GRID-11B at T0 = 2026-02-07 13:12:10 UTC. This burst was simultaneously detected by three GRID nanosatellites, marking the first event jointly observed by three GRID satellites. Temporal analysis of the main emission yields a duration of T90 = 0.42 ± 0.08 s in the 30–2000 keV energy range. Although extended emission appears to be present, the limited sensitivity of GRID does not allow for a detailed characterization of this component. At the trigger time, GRID-10B was operating in 1 s bin mode, which prevents a refined localization. Nevertheless, the reconstructed direction is consistent with the position reported by Fermi-GBM. At present, only the GRID light curve is available. Spectral analysis is not yet reported. The GRID light curve of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB260207B/GRID_GRB2... GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to: https://doi.org/10.1007/s10686-019-09636-w, https://doi.org/10.1007/s10686-021-09819-4. View this GCN Circular online at https://gcn.nasa.gov/circulars/43710. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...