Charged protons . . .
Particles are always coming in, charging the aroras. The average speed is approx. 400 km/s.
Yeah, they be bookin',man!
Photons, being packets of light, are, of course, much faster, very near the ultimate speed of light, which I don't think can be naturally attained and held, with all the minute impurities we have in the Solar System. A photon is an early warning of proton-crowds to come, such as sparking notification of a notoriuos CME, the larger of which have the potential to overload some of our more antquated power grid switches, resulting in regeonal blackouts.