EP241021a: No Detection in Fermi-GBM Observation

Fermi-GBM had full spatial and temporal coverage of the EP WXT signal of EP241021a (Hu et al., GCN 37834). There was no Fermi-GBM onboard trigger around the event time of EP241021a. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM also identified no counterpart candidates. The GBM targeted search, the most sensitive, coherent search for GRB-like signals, was run from 30 s before the EP trigger time until 300 s after, seeking signals between 64 ms and 32.768 s in duration. A candidate was found, but it has a localization that is not consistent with the EP trigger and appears to be a soft Galactic source that becomes occulted by the Earth at approximately T0+40 s. No signal consistent both temporally and spatially is identified, as confirmed by visual inspection of the data.