Think about it. You observe changes in a star 8 light-hours away from earth, and radio your observations back. What speed do the radio waves travel at? c. What speed does the light bearing the original observation travel at? c. What speed does the supernova blast travel at? also c. Neutrinos travel so close to c it makes no difference.
If observed changes to a star happen well before the supernova event itself then the fact that everything is happening at c doesn’t matter. Say for example that the neutrino flux increase happens 24 hours before hand. That means we have a 24 hour warning before the supernova event. Similarly, if we see an increase in luminosity before the supernova we still get advance warning. What matters is that there is a delay between when stars show signs of supernovaing and when they actually supernova.
The point is that being closer to the star when that happens doesn’t provide you with more forewarning than if you look at it from home.
I don’t think anyone is advocating that we send actual probes to Betelgeuse or IK Pegasi. I’m confused why one would think that would even be on the table. Even if we sent a probe today at a tenth of the speed of light (well beyond our current capabilities) it will still take around 1500 years to get to IK Pegasi. I don’t know why one would even think that would be at all in the useful category.
What is helpful is having more space based observation equipment in our solar system. The more we put into space the less of a problem we have with atmospheric interference, artificial radio sources, and general light pollution. To use one specific example that would help a lot, if we had a series of optical telescopes that were spread out around the solar system we could use parallax measurements to get a better idea how far away Betelgeuse is. For a variety of reasons there’s a lot of uncertainty about how far away it is with 330 light years as a lower estimate and around 700 as an upper estimate although it seems like around 640 is where things seem to be settling down at. Given the inverse square law for radiation, this matters for a supernova concern. A difference of 300 light years corresponds to about a factor of 4 in the radiation strength. Overall, most of the interesting, practical investigation and reduction of astronomical existential risks can be done right here in our home system.
If observed changes to a star happen well before the supernova event itself then the fact that everything is happening at c doesn’t matter. Say for example that the neutrino flux increase happens 24 hours before hand. That means we have a 24 hour warning before the supernova event. Similarly, if we see an increase in luminosity before the supernova we still get advance warning. What matters is that there is a delay between when stars show signs of supernovaing and when they actually supernova.
The point is that being closer to the star when that happens doesn’t provide you with more forewarning than if you look at it from home.
I don’t think anyone is advocating that we send actual probes to Betelgeuse or IK Pegasi. I’m confused why one would think that would even be on the table. Even if we sent a probe today at a tenth of the speed of light (well beyond our current capabilities) it will still take around 1500 years to get to IK Pegasi. I don’t know why one would even think that would be at all in the useful category.
What is helpful is having more space based observation equipment in our solar system. The more we put into space the less of a problem we have with atmospheric interference, artificial radio sources, and general light pollution. To use one specific example that would help a lot, if we had a series of optical telescopes that were spread out around the solar system we could use parallax measurements to get a better idea how far away Betelgeuse is. For a variety of reasons there’s a lot of uncertainty about how far away it is with 330 light years as a lower estimate and around 700 as an upper estimate although it seems like around 640 is where things seem to be settling down at. Given the inverse square law for radiation, this matters for a supernova concern. A difference of 300 light years corresponds to about a factor of 4 in the radiation strength. Overall, most of the interesting, practical investigation and reduction of astronomical existential risks can be done right here in our home system.
So the benefit of space-based observation is signal amplification rather than signal speed.
In a nutshell yes. And the more signal amplification we get the quicker we can detect problems before it is too late.