So, about "planet nine" or "planet x"

[AppleDumplingHead]

Can anyone explain to me, in two or three paragraphs, why a hypothetical object orbiting the sun at a distance @1ly, in the Oort cloud, approximately the mass of 10 Earths, is not a "micro", or otherwise small, black hole remnant of a former stellar companion to Sol?

 

[GoodSarmatian]

Is this about the hypothetical Nemesis Object ?
Whatever it is, it can't be a black hole of any kind. A "small" black hole wouldn't have the mass to sustain itself and would quickly "evaporate" into radiation.
One hypothesis is that it might be a brown dwarf which is a huge gas giant that isn't quite large enough to be a star because it can't generate enough gravitational pressure for nuclear fusion to occur.

 

[red_elk]

From what I remember, black hole remnant of a star should have much larger mass than the Sun. If it's a black hole with mass of just ten Earths, it should have size of about golf or tennis ball.
Brown dwarf also can't be such small. Even Jupiter's mass (~300 Earths) is not enough to form a brown dwarf.

 

[AppleDumplingHead]

Is this about the hypothetical Nemesis Object ?
Whatever it is, it can't be a black hole of any kind. A "small" black hole wouldn't have the mass to sustain itself and would quickly "evaporate" into radiation.
One hypothesis is that it might be a brown dwarf which is a huge gas giant that isn't quite large enough to be a star because it can't generate enough gravitational pressure for nuclear fusion to occur.

Yes, it is this https://en.wikipedia.org/wiki/Planet_Nine, which has garnered considerable steam in popular science clickbait, lately.

I don't know that I agree the statement, that " A "small" black hole wouldn't have the mass to sustain itself and would quickly "evaporate" into radiation. " , because we'd need to first define "quickly", and we would need to argue it's in a vacuum without potential "fuel". It very well might be sustaining itself with material from the Oort cloud. How apparent would be an accretion disk of an object the size of a basketball, but with the mass of 10 Earths? It would probably, I'd think, "look like" a "dark spot" in spacetime, roughly the size of a planet with the mass of 10 Earths.

I appreciate your answer, and I know the general consensus is that it's a planet (ish?) object. I just have this image of a stellar "explosion" of our sun's binary companion which released much of the mass now transiting sol, billions of years ago, which coalesced to the formation of what we see today. The "remnant" of that reaction, a small "black hole" still persists on the outer edge of the sun's gravity. All the planetary, asteroid, comet "chunks", are also the result of that event. I don't understand why that, somehow, doesn't make sense.

 

[uppi]

Whatever it is, it can't be a black hole of any kind. A "small" black hole wouldn't have the mass to sustain itself and would quickly "evaporate" into radiation.

For 10 earth masses that would take much longer than the age of the universe. We have no evidence of black holes this size, but there is no reason they could not exist.

 

[Michkov]

Much more reasonable to assume its a 10 earth mass planet (a type of objects we know exist, two in our own solar system even), rather than a black hole of that size. Which as uppi pointed out we have never seen.

As for the "explosion" you imagine most of that material would be spread over a too large distance over billions of years, so you'd have to have it happen closer to the present which messes with our existence. Super Novae are not something you want going off in your backyard if you want to keep living.

 

[AppleDumplingHead]

As for the "explosion" you imagine most of that material would be spread over a too large distance over billions of years, so you'd have to have it happen closer to the present which messes with our existence. Super Novae are not something you want going off in your backyard if you want to keep living.

Well, no, I was actually implying the event would have happened 4.5 to 5 billion ya, and all this matter in the solar system is what, of that, was collected by Sol.

You're probably right, though, that it's more reasonable to expect it to be a planet.

 

[warpus]

It's probably just a very large teapot

 

[hobbsyoyo]

It probably doesn't exist, unfortunately.

 

[Kyriakos]

Planet 9 from outer space?