News: 1607686452

... to think they'd discovered an exoplanet the size and distance of Pluto?

Look, it's over. It's finished. It's not a planet.

And the real planet 9 would be way cooler - mainly because it would be that much farther from the sun.

What puzzles me is the fact that the object's existence and orbit are uncertain, therefore it is hard to see how it can be known to have cleared the neighborhood around its orbit. So calling it Planet 9 seems a mite premature.

Maybe cooler, but how much heat does our planets core generate? And we're just a little kitty planet compared to that one...

I think this discovery is a good example of how human science works, we've seen something interesting and we're thinking about what happened, and how it might have happened. And one day maybe we will know.

Jovian planets can generate a lot of heat. Jupiter emits significantly more energy than it receives from the some; this is powered by the planet's contraction (as I recall, it's diameter shrinks by about 1 cm per century). Certainly a Jovian or super-Jovian planet in the sort of a highly distant orbit proposed for Planet 9 would probably have the same characteristics and should stand out to a good IR telescope, if only we knew in which direction to point it!

@BAG

Sun.

If you are working soley from occlusion then a small black hole may not have enough gravity for lensing

A black hole of 11 Jupiter masses would have a radius of about 30 m so I doubt you would detect it by occulusion measurements. Also I am not clear how such an object could form unless it was some wildly improbable fragment left over from the big bang.

A few years ago I joined a Zooniverse project that was looking for brown dwarfs and/or planet 9. I somehow managed to find nothing but other folk did indeed spot viable objects.

I love the terminology these astroboffins use......

Nudged by a passing star. It conjures up a stellar snooker game.

Billiards with gravity :0)

Nudged back by a passing star seems to be a very tight set of circumstances where the passing star effectively imparts a 180 degree about turn.

My thinking is that after formation some planets will eventually come into close enough proximity to result in collisions or major orbital changes. Any planets gaining enough velocity from such an encounter has the possibility of escaping the local stars gravity well, so it follows that they can also be captured if they intersect* with another solar systems gravity well and there must be a lot of cold dark planets whizzing through the void.

It feels to me more likely that the vast majority of eccentric orbit results from either purely internal dynamics or being captured by another star entirely.

* A narrow band between falling into the star or another course change into the void for another bite at getting captured.

LISTER: Let me get this straight. Is she doing what I think she's doing?

CAT: Why? What DO you think she's doing?

LISTER: Playing pool with planets.

RIMMER: Is that possible?

LISTER: Well, it's not going to work. It's completely insane. It's

whacko. It's noodle-doodle.

CAT: I'm with you, buddy.

LISTER: No, not the idea, the shot. There's not enough side.

RIMMER: "Side?"

LISTER: Yeah, side-spin. It's a complete mis-cue.

RIMMER: What are you drivelling about, Lister? We're talking about a

computer with an IQ in excess of twelve thousand.

LISTER: Doesn't mean she can play pool. I can. Trust me. I know

whereof I speak. Aigburth Arms on a Friday night. They used to call

me Dave "Cinzano Bianco" Lister 'cause once I was on the table, you

couldn't get rid of me. This pool arm is as sound as a dollarpound,

and I promise you that shot _will not come off_. She's topped it,

that's what she's done, she's topped it! It's a felt-ripper! That

planet is off the table and into somebody's pint of beer.

RIMMER: We are talking about the trigonomics of four-dimensional space,

you simple-minded gimboid! We are not talking about some seedy game of

pool in a backstreet Scouse drinking pit.

LISTER: It's the same principle.

RIMMER: Of course it isn't!

LISTER: Rimmer, I promise you, THAT is a complete mis-cue. I say we

chuck Holly's coordinates in the bin and let ME take the shot.

RIMMER: Well, I say we put it to the vote. On one hand, we have a

computer, with an IQ in excess of twelve thousand, who has a total

grasp of astrophysics. And on the other hand, we have Lister, who, and

let's be fair to him, is a complete gimp. To whom do we entrust our

lives, the safety of this vessel and the future of everything? If it's

a tie, we go with Holly. What's your vote, Lister?

LISTER: Well, I vote for Dave "Cinzano Bianco" Lister.

RIMMER: One-nil to Listypoos. I vote for Holly. Cat?

CAT: Well, I agree with you, buddy. But I'm voting for Doodoo Breath.

The thing is, even though you're right, I could not bring myself to

vote for someone with your dress sense. I couldn't put my cross next

to the Bri-nylon party.

RIMMER: Down to you, Kryten.

KRYTEN: Well, I agree it's insane and suicidal, Sir, but I'm afraid I

have to side with the human.

LISTER: Brutal!

RIMMER: You're voting for El Dirtball?

KRYTEN: It's in my programming, Sir. A living human outranks a hologram.

I'm sorry.

LISTER: Three-one to me! Let's do it!

RIMMER: Congratulations, Kryten. Your vote has just killed everyone.

CAT: Will you relax? I've seen Gerbil-Face play down in the Recreation

Room. He's a diva! He can knock those striped balls around the table

all night long, and I tell you what, I have never once seen him lose a

single ball down one of those holes!

I've seen it claimed that once the Vera Rubin survey telescope begins operation, it should be able to find planet 9 (if it exists) in less than a year even if it happens to be a small black hole.

For some reason, I read that as 'the propane planet's...'

I hope they call it Plan 9 (from Outer Space, natch).