Asdfex did an absolutely superlative job explaining why it's probably just background stellar emissions we're seeing, but let me ask you this: Who said a sun can't be an engine?

If you're willing to posit the existence of Megastructures (that we can't directly detect) then I offer you the Shkadov Thruster

It's basically an immense photon-sail pushed by nearly half the output of a star. Its size allows it to gravity-tractor its powering star (and solar system) along with it, turning it into a literal starship.

Note: I don't think this is even remotely possible, I'm just giving you an edge-case where ion emissions can be the result of alien propulsion.

Asdfex did an absolutely superlative job explaining why it's probably just background stellar emissions we're seeing, but let me ask you this: Who said a sun can't be an engine?

If you're willing to posit the existence of Megastructures (that we can't directly detect) then I offer you the Shkadov Thruster:

It's basically an immense photon-sail pushed by nearly half the output of a star. Its size allows it to gravity-tractor its powering star (and solar system) along with it, turning it into a literal starship.

Note: I don't think this is even remotely possible, I'm just giving you an edge-case where ion emissions can be the result of alien propulsion.