[perihelions]

Related: last month's [0] gamma-ray burst also had interesting, measurable effects on the ionosphere,

https://gcn.gsfc.nasa.gov/gcn3/32744.gcn3 ("GRB221009A: Detection as sudden ionospheric disturbances (SID)")

https://www.qsl.net/df3lp/grb221009/KLM_grb221009a_magnitude... (from the above link)

http://abelian.org/vlf/grb221009a-DHO.png

http://abelian.org/vlf/grb221009a-NAA.png

http://abelian.org/vlf/grb221009a-NSY.png

[0] https://news.ycombinator.com/item?id=33215572 ("Record-breaking gamma-ray burst possibly most powerful explosion ever recorded")

This was detected with VLF radio, but I wonder if this kind of event also has an effect on GPS signals? The time-of-arrival of astrophysical gamma rays isn't uniform across the earth.