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Full Version: (Paper) Evidence of a Jovian Mass Solar Companion in the Oort Cloud?
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Paolo
[Posts moved from "INCOMING" discussion.]

... a new confirmation of the "Nemesis" theory Persistent Evidence of a Jovian Mass Solar Companion in the Oort Cloud
ngunn
Much appreciated, thanks. Best of all the full article is available free.
Hungry4info
I think calling it a "confirmation" is giving it a bit too much credit, but it is interesting nonetheless.
As they state, WISE will shed much more light on the issue.
Phil Stooke
This certainly can't be called a confirmation, as Hungry4info already said. Let's see how the paper is received. I'd love to see such an object discovered (though I don't see how it could have been missed in the past) - what a target for a New Horizons-type mission! But I'm not very hopeful.

Phil
Greg Hullender
Some interesting points (this thing is over 40 pages long!)

1) They reject the "Nemesis" concept, saying the object couldn't cause "comet storms."
2) They want to name it "Tyche" for the good sister of Nemesis.
3) They're talking 1-4 MJ at 10,000 to 30,000 AU; to put that in perspective, note that even a probe like NH would take thousands of years get there.
4) It's inclined 133 degrees to the ecliptic, but they think the orbit's circular.
5) Depending on assumptions, they give as much as a 50% chance that this is an illusion caused by randomness in the observations.

Within year, WISE will know. Gives us something to anticipate though.

--Greg
Paolo
QUOTE (Hungry4info @ Apr 27 2010, 12:35 PM) *
I think calling it a "confirmation" is giving it a bit too much credit


you are right. I should have used another word, but my capability of thinking in English at 7 AM is not very good...
stewjack
QUOTE (Greg Hullender @ Apr 27 2010, 11:07 AM) *
Some interesting points (this thing is over 40 pages long!)
--Greg

Not to mention that it has Math in it. Math! I might, just might, read 40 pages of words and pictures. But Math - no way! wacko.gif
Thanks Greg
tedstryk
Yeah, why in the world would they use math in trying to determine whether the effects of a massive object in the Kuiper Belt are present? rolleyes.gif Next thing you know they will start using it in computing spacecraft trajectories.
stevesliva
QUOTE (tedstryk @ Apr 27 2010, 02:07 PM) *
Yeah, why in the world would they use math in trying to determine whether the effects of a massive object in the Kuiper Belt are present? rolleyes.gif


Because strong in them the force is not.
ngunn
Whether this object exists or not there is plenty of room for them in the unsearched parameter space. I'm surprised Phil thinks anything out there would have been discovered already. How, I wonder?

Agreed, 50 percent is not a great probability. Most researchers wait for 95 percent before publishing.
nprev
The merits of math aside, statistical inference is always to be taken with a grain of salt on its own. To paraphrase a quote I once heard, 'You can prove anything with a logarithmic chart!' tongue.gif

I see this paper as a bit of a roll of the dice by the authors. WISE might conceivably spot such an object; if it does, then they might go down in history as the 21st Century equivalents of Leverrier & Adams.
alan
This paper reminds me of an article I read in Sky and Telescope ~20 years ago which also speculated that a group of comets with aphelia on a narrow band of galactic longitude were due to distant solar companion. I'll have to see if I can locate a copy.
Phil Stooke
I was assuming that IR surveys - going right back to IRAS - would have picked up anything this size.

Phil
nprev
They do mention IRAS, and sort of artfully adjust their constraints to account for the fact that it was not in fact previously discovered.

Well, the best part of this hypothesis is that it can be tested fairly rigorously. A lot of us here have been half-expecting WISE to discover at least one massive body closer than Proxima as discussed in other threads, and "half-expecting" is precisely the numerical probability assigned by the authors to this putative distant Jovian! smile.gif
Vultur
I hope this works out, and that WISE finds the object .. but can it? I remember reading that WISE couldn't find an Earth-size body at Kuiper belt (or was it Oort cloud?) temperatures. At that distance from the Sun, it'll be *really* cold ... but at Jupiter-mass plus, it should produce a significant amount of internal heat.

'Tyche' is a clever name.

QUOTE (Greg Hullender @ Apr 27 2010, 05:07 PM) *
3) They're talking 1-4 MJ at 10,000 to 30,000 AU; to put that in perspective, note that even a probe like NH would take thousands of years get there.


Yeah, if it exists, it'll take a new generation of propulsion technologies to get there in anything resembling a reasonable time. Presuming 20,000 AU, to get there in twenty years would require an average speed of 4740 km/s.
Greg Hullender
QUOTE (Vultur @ Apr 28 2010, 12:29 PM) *
Presuming 20,000 AU, to get there in twenty years would require an average speed of 4740 km/s.

Note that 10,000 AU is about two light-months, and 30,000 AU is about half a light-year.

We're talking really, really far here.

--Greg
Stu
Great, something ELSE to add on to our Solar System Scale Model... !

smile.gif
PFK
QUOTE (Stu @ Apr 29 2010, 06:34 AM) *
Great, something ELSE to add on to our Solar System Scale Model... !

smile.gif

At your scale, 20k AU = 340km. According to GoogleEarth, Kendal Castle to Wembley Stadium 348km. Bingo! smile.gif
Stu
Brilliant! Thanks PFK, you just scribbled one item off my To Do list for me! laugh.gif

Big_Gazza
Not wanting to inject controversy into this thread laugh.gif but if Tyche does indeed exist, would the current IAU "rules" result in this object being considered a planet or a "dwarf"? Its a good assumption to believe the object will have reached hydrostatic equilibrium and be a spheroid, but has it cleared its neighbourhood of debris and minor objects?

Wouldn't it be ironic (hilarious) if Sols largest companion was classified by IAU as a dwarf planet due to a technicality?
brellis
Wouldn't Jupiter have to be upgraded to "Failed Star"? rolleyes.gif
Hungry4info
I interpret the rule to mean that the object has to gravitationally dominate its region of space. Thus Earth, Jupiter, and Neptune are still planets, as would be "Tyche."
Vultur
What is the total mass of the Oort Cloud? I'm pretty sure it is vastly less than 1 Jupiter mass (as supposedly Jupiter outweighs everything else in the System combined, except the Sun) in which case this object would (as I understand it) be considered dominant in its region, as it outweighed all the debris in its orbit (as, say, Ceres doesn't.)
nprev
I wouldn't be surprised it's vastly less than an Earth mass...probably less than even that of the Moon. Lotta snowballs out there, not much rock.
Greg Hullender
I see it estimated anywhere from 40 Earth masses to as little as 1.

Lots of Oort, not so much cloud. ;-)

--Greg
brellis
It gets a little confusing to hear about the Voyagers approaching one type of solar system boundary, while the Oorties are so much further out there! huh.gif
dmuller
What's the Hillsphere of the Sun?
centsworth_II
QUOTE (dmuller @ Oct 2 2010, 02:37 AM) *
What's the Hillsphere of the Sun?

From this quick Google grab:
"If it is agreed to assume a Hill sphere for the boundaries of the solar system [230,000au],
it is found that these boundaries extend to the nearest stars. However, stable motion of the
planets (with direct motion) probably is possible only within the solar gravitational sphere. [4500au]"
Click to view attachment
nprev
I was going to ask why the radius of the Sun's Hill sphere would have to be "assumed", but then I found this calculator to approximate it. Since it involves the masses of two bodies, I guess that a sufficiently massive planet could be in solar orbit at a considerable distance (much greater than I'd thought possible).
centsworth_II
Looking back to the previous page (621) to the page I link (622), It looks like the two bodies used are the sun and the whole galaxy. The major assumptions are the mass of the galaxy and assuming that mass to be concentrated at the center of the galaxy. I wonder if more recent calculations deviate much from this one.
centsworth_II
Flurry of tweets at #dps2010:

"Hal Levison proposing protoplanetary disks of *other* nearby stars as source of Oort Cloud comets..."
dmuller
QUOTE (nprev @ Oct 2 2010, 06:42 PM) *
Since it involves the masses of two bodies, I guess that a sufficiently massive planet could be in solar orbit at a considerable distance (much greater than I'd thought possible).

I thought that the two masses involved in the calculation are M = mass of center of Milky Way (or entire MW?) and m = mass of Sun, making the hillsphere not a variable of whatever circles around the Sun. I may be very very wrong though!
brellis
Is there a way to measure the 'wobble' of our own beloved star? Could it be reflected in position data from the Voyagers or Pioneer?
Lunik9
Interesting Tyche theory but different with the Nemesis theory, as the latter is about a Brown Dwarf object (12 to 75 Jupiter masses) or a Red Dwarf star. Tyche theory speaks about a Jovian mass planet 1 to 4 Jupiter masses.
When PAN-STARRS & LSST become operational, astronomers will find out more and we'll see if the sharp outer edge of the Edgeworth-Kuiper belt (and the inclined orbits of SDOs) can be explained.
I believe there's even a theory of a Black Hole in the vicinity of the outer Oort cloud?
Greg Hullender
QUOTE (Lunik9 @ Oct 5 2010, 03:27 AM) *
Interesting Tyche theory but different with the Nemesis theory, . . . I believe there's even a theory of a Black Hole in the vicinity of the outer Oort cloud?

I think you mean "hypothesis" not "theory" here. From the lack of press releases on the subject from WISE, my own hypothesis is that they didn't find any of these objects within a light year of Sol.

--Greg
qraal
Another paper available on the arXiv which is germane to this discussion is Lorenzo Iorio's piece...

The perihelion precession of Saturn, planet X/Nemesis and MOND

...the abstract of which I quote...

QUOTE
We show that the retrograde perihelion precession of Saturn \Delta\dot\varpi, recently estimated by different teams of astronomers by processing ranging data from the Cassini spacecraft and amounting to some milliarcseconds per century, can be explained in terms of a localized, distant body X, not yet directly discovered. From the determination of its tidal parameter K = GM_X/r_X^3 as a function of its ecliptic longitude \lambda_X and latitude \beta_X, we calculate the distance at which X may exist for different values of its mass, ranging from the size of Mars to that of the Sun. The minimum distance would occur for X located perpendicularly to the ecliptic, while the maximum distance is for X lying in the ecliptic. We find for rock-ice planets of the size of Mars and the Earth that they would be at about 80-150 au, respectively, while a Jupiter-sized gaseous giant would be at approximately 1 kau. A typical brown dwarf would be located at about 4 kau, while an object with the mass of the Sun would be at approximately 10 kau, so that it could not be Nemesis for which a solar mass and a heliocentric distance of about 88 kau are predicted. If X was directed towards a specific direction, i.e. that of the Galactic Center, it would mimick the action of a recently proposed form of the External Field Effect (EFE) in the framework of the MOdified Newtonian Dynamics (MOND).
kap
QUOTE (qraal @ Dec 22 2010, 01:55 AM) *
Another paper available on the arXiv which is germane to this discussion is Lorenzo Iorio's piece...

The perihelion precession of Saturn, planet X/Nemesis and MOND

...the abstract of which I quote...


Am I correct in thinking only a captured body could be in orbit completely perpendicular to the ecliptic? Something 80-150 AU and the size of Mars or greater certainly would have been seen by now, even if it's orbit was extremely inclined. Unless it's somehow being obscured...

-kap
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