16 upvotes, 4 direct replies (showing 4)
View submission: Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science
In principle, yes - both are just objects with a particular mass. Black holes only start behaving weirdly once you get inside the event horizon, but that wouldn't affect the sort of distances where stable orbits would occur.
However, I think that in both cases they would be unlikely. The formation of a black hole would probably destroy any existing planetary system, so the planet might have to be captured later. Not sure about pulsars, but presumably the surface of any such planet would be totally blasted by radiation.
Comment by atomfullerene at 20/07/2022 at 15:00 UTC
9 upvotes, 2 direct replies
The very first planetary system ever discovered was around a pulsar. Presumably if you can do interstellar travel you can handle the radiation, although I'm sure it's pretty high.
Comment by [deleted] at 20/07/2022 at 14:47 UTC
1 upvotes, 0 direct replies
Thank you!
Comment by kftrendy at 20/07/2022 at 16:47 UTC*
1 upvotes, 0 direct replies
The formation of a black hole would probably destroy any existing planetary system
There are scenarios where the BH forms without a supernova. With enough mass you can get things to collapse fast enough to avoid getting a SN. That doesn't mean there's *zero* emission while the star collapses - you would still get some outer layers blown off and an increase in luminosity just due to the initial collapse - but you avoid the supernova itself, so more possible for planets to stick around without being vaporized.
I'm not sure what characterizes "fast enough" - maybe you avoid creating the proto-neutron star at the core that you usually create in a core-collapse SN? Without the proto-NS, infalling material won't have anything to bounce off of, so you wouldn't get the initial outward shock of the SN. Or maybe the burst of neutrinos created in the process start out gravitationally bound? If a good fraction of the neutrinos are bound rather than flying out of the star, then you might not get enough energy out of the core to sustain the SN. The exact mechanism of supernova formation isn't 100% understood (in particular, we aren't sure about how you get from the initial "bounce" to the full SN, as a lot of calculations seem to suggest that the shock should stall out before it can produce the SN).
Comment by TOTALLYnattyAF at 20/07/2022 at 21:32 UTC
1 upvotes, 2 direct replies
Another issue here would be time dilation. Generations could go by while the explorers attempt to explore the surface of the planet. It does provide for the stunningly terrifying idea that you could be on a planet and look up and see a black hole in the sky. I guess Christopher Nolan will have to incorporate it into his next movie.