"Aernus", A proposed new planet in the Kuiper Belt Options

[tuvas]

Interesting. A massive distant planet is one way to account for the orbit of Sedna. I don't know if one Earth mass is enough though.

If one earth mass wasn't enough, maybe they are in some kind of a resonance. That would allow for a difference in orbit gradually over time. That might even help to find such an object...

[ustrax]

I've asked David Tholen (the responsible for the latest Pluto system images) about this, if he had knowledge of it, I didn't publish this in the blog because it was a bit off topic, but there's one thing he said that made me scratch my head more vigourously...
He told me that he was aware of predictions for a much larger object being even farther out...

[ngunn]

He told me that he was aware of predictions for a much larger object being even farther out...

What? - Just one?

[SigurRosFan]

Here's the arXiv preprint:

- An Outer Planet Beyond Pluto and Origin of the Trans-Neptunian Belt Architecture

[ngunn]

Thanks very much for that - duly printed off for holiday reading.

[ustrax]

Patryk Lykawka provided the link for downloading the high quality PDF (8.84MB) directly from his site.

[marsbug]

Thanks ustrax that'll make for fascinating lunch break reading!

[alan]

New Scientist has an article discussing Lykawka's theory in the Jan 12 issue.
http://space.newscientist.com/article/mg19...f-planet-x.html

Levison and Morbidelli have there own paper to explain the properties of the Kuiper belt.
http://arxiv.org/abs/0712.0553

[Greg Hullender]

MSNBC is running a story on this today:

http://harbor.scitec.kobe-u.ac.jp/~patryk/...a-Planetoid.pdf

Apparently Patryk has a new paper in the Astrophysical Journal today, although I can't find a link to it on his site:

http://harbor.scitec.kobe-u.ac.jp/~patryk/index-en.html

My biggest question, though, is why he thinks it would only be a "plutoid," since he seems to be describing a very large (Earth-diameter, but 1/3 mass) object well outside the Kuiper Belt -- something that almost certainly would have cleared its orbit.

--Greg

[nprev]

I think he's erring on the side of caution and using the largest category of currently recognized trans-Neptunian objects by the IAU; seems sensible to me.

If you think the Pluto debate has been a debacle, just wait 20 years or so when I personally think we'll find a couple of dozen Mars-sized or better objects out there to struggle with. I'm gonna go with Stephen's nomenclature on another thread and start using "thingys".

[Alan Stern]

MSNBC is running a story on this today:

http://harbor.scitec.kobe-u.ac.jp/~patryk/...a-Planetoid.pdf

Apparently Patryk has a new paper in the Astrophysical Journal today, although I can't find a link to it on his site:

http://harbor.scitec.kobe-u.ac.jp/~patryk/index-en.html

My biggest question, though, is why he thinks it would only be a "plutoid," since he seems to be describing a very large (Earth-diameter, but 1/3 mass) object well outside the Kuiper Belt -- something that almost certainly would have cleared its orbit.

--Greg

At Pluto's orbit, Earth would not be a planet by IAU standards. Silly, I know. At 100 AU, a several Earth mass object would be disqualified. This is a consequence of the zone clearing criteria which biases what is and is not a planet by distance-- so that objects that are planets at 1 AU like Earth are not planets at 30 AU. You know what I think of this. Now for a prediction: It shall fall before NH reaches Pluto. Too many people are figuring it out. Google "Great Planet Debate."

-Alan

[ElkGroveDan]

Organizations such as IAU exist by virtue of broad agreement to accept their declarations and rulings. When these groups tread outside the bounds of popular opinion and become controversial they risk that universal acceptance and accordingly their usefulness as an organization comes into question. Not that I'm part of any cabal, or anything like that.

[nprev]

(Sigh)...yeah, and it's a damn shame that it happened, too. Up till this point, the IAU has been one of the least controversial and most respected organizations there is. Unfortunately, I think it was inevitable as well, and there will be other emerging issues in the near future as well (for example, let's all try to obtain a precise definition of a brown dwarf once we've got a broad sample of their population; ain't gonna be pretty.)

Classification in an absolute human-subjective sense does not lend itself well to almost any feature or aspect of the actual Universe. Reality stretches our self-imposed boundaries, always. Just watch: we're gonna find things like 'galaxies' in intergalactic space with fewer stars than an open cluster. The naming of names will never be over.

For the far future, wait till when and if we ever discover a complex alien ecosystem; the words 'animal' and 'plant' will become instantly obsolete. Hell, they already are in a lot of ways.

Sorry to belabor the point. I just don't ever see a neat solution to the problem, and it goes far beyond astronomy.

[JRehling]

Even beyond the controversy, we've had the following categories invoked re: Pluto's possible membership in the past several years:

Planet (pre-2006 status)
Planet (the definition it had for a few days including Ceres, Eris, and Charon)
Planet (the latest definition, excluding Pluto)
Minor Planet (re: proposals to give it a Minor Planet number)
Dwarf Planet
Kuiper Belt Object
Trans-Neptunian Object
Plutino
Plutoid
Planetoid?

Pluto is in six to eight of these categories by the current official reckoning, which is remarkable when you consider that we don't know that much about it. This is a mess. It was honestly someone's idea to look at the previously existing nine categories and conjure up a new one?

How many times can you screw up a joke before the audience wants you off the stage? The IAU is *way* past that limit.

[tasp]

My apologies if someone else has thought of this first and I didn't notice (or if it is impossible . . . )

IIRC, quite a few objects out Pluto way seem to be resonant with Neptune. (3:2 springs to mind)

Are any other solar orbital periods suspiciously common amongst the remainder of the other objects ??

Or any commensurabilities??


Like if we are seeing several objects with periods around (just picking a random #) 313 years and another bunch at 469 years, it seems like something "might be up".

Maybe something large out at 626 years, or 939 years?

(I realize checking all the ratios is annoying and involves something called 'math' . . . . )