SIMBAD references

We report the detection of a significant sudden ionospheric disturbance in the D-region of Earth's ionosphere (∼60-100 km), which was associated with the massive γ-ray burst GRB 221009A that occurred on 2022 October 9. We identified the disturbance over northern Europe-a result of the increased ionization by X- and γ-ray emission from the GRB-using very low frequency radio waves as a probe of the D-region. These observations demonstrate that an extra-galactic GRB (z ∼ 0.151) can have a significant impact on the terrestrial atmosphere and illustrates that the Earth's ionosphere can be used as a giant X- and γ-ray detector. Indeed, these observations may provide an insight into the impacts of GRBs on the ionospheres of planets in our solar system and beyond.