SaltyDangerHands t1_jd56e6v wrote on March 21, 2023 at 10:23 PM

At this point, the answer is "probably not".

There's been a bunch of math and predictions to indicate there might be, it's possible, but every time someone says they've figured out where it is, where it should be, it.... isn't.

At this point, it's hard to imagine missing anything significant, or at least, anything significant that reflects light, like a planet would.

A small, stellar black hole, however, could easily remain undetected directly while still showing up regularly and frustratingly in our math. Is it likely? No, not at all. But it's possible, and that's fun, the idea that we might have a black hole orbiting our sun beyond Neptune is a fun one.

astrocomrade t1_jd5eoal wrote on March 21, 2023 at 11:20 PM

I agree it's best to be skeptical here but folks are pinning this alleged planet nine at an apparent magnitude greater than 20/21 That's very faint, even by modern standards. While that's not out of reach in big telescopes, it's time intensive and you'd need to know bang on where to look.

That magnitude is near the limit of most of the ongoing all sky surveys, so it's not particularly surprising that it wouldn't yet show up that way were it to exist. In that respect at least I don't think it's fair to totally rule it out because we don't see it yet. That's way harder than it might initially might seem. Things as far away from the sun as this is proposed to be are going to be really difficult to detect via the ole' photon collection method regardless of size.

pompanoJ t1_jd5nm6z wrote on March 22, 2023 at 12:24 AM

There could also be a huge planet way out near the oort cloud. With an orbital period in the thousands of years and a temperature near the background, it might take a tremendous stroke of luck to find it before we have a flotilla of Webb class space telescopes dedicated to the topic of outer solar system objects.

NotMalaysiaRichard t1_jd6roem wrote on March 22, 2023 at 6:29 AM

A small stellar sized black hole would be on the order of at least 3 solar masses. It would mean that we were part of a binary system with a supernova or somehow the solar system captured a rogue black hole. I’m not an astrophysicist but I‘m not sure what the orbital dynamics of that scenario would entail. I’m assuming you’re actually referring to a primordial black hole, something formed during the Big Bang, which could theoretically have smaller masses?

SaltyDangerHands t1_jd8f7q4 wrote on March 22, 2023 at 4:05 PM

I mean, it's not my theory, I'm most certainly not an astrophysicist either, so it could well be a primordial one, sure. I think the documentary in which I saw it mentioned, and I couldn't tell you the name, they're my background noise, the idea that it was captured as opposed to native to our solar system.