We know that light and even gravitational waves propagate at the speed of light.
So if something catastrophic happened to the black hole at the center of our galaxy (about 26,000 lightyears away), would there be any way for us to have advance knowledge of it before we could observe it with telescopes or before we could measure the gravitational changes?
Ludicrous example: say the black hole at the center of the galaxy disappeared 25,999 years ago. Is there a way we would have known about it by now, or do we just have to wait out another year to see if we’re all screwed?
Any data is sent at or below the speed of light. Solar storms are charged particles (mostly protons) being ejected from the sun and eventually hitting the earth’s magnetic field, causing disruptions in the field (and potentially cool auroras).
Since these storms are just particles traveling from the sun to the earth, they travel slower than light speed, so our distant sensors can warn us in advance at/near the speed of light. This won’t work if the sun were to instantly disappear or change color though, that information would travel at light speed and the probe signals would arrive at the same time.