More support for Planet Nine

More support for Planet Nine
This illustration depicts orbits of distant Kuiper Belt objects and Planet Nine. Orbits rendered in purple are primarily controlled by Planet Nine's gravity and exhibit tight orbital clustering. Green orbits, on the other hand, are strongly coupled to Neptune, and exhibit a broader orbital dispersion. Updated orbital calculations suggest that Planet Nine is an approximately 5 Earth mass planet that resides on a mildly eccentric orbit with a period of about ten thousand years. Credit: James Tuttle Keane/Caltech

Corresponding with the three-year anniversary of their announcement hypothesizing the existence of a ninth planet in the solar system, Caltech's Mike Brown and Konstantin Batygin are publishing a pair of papers analyzing the evidence for Planet Nine's existence.

The papers offer new details about the suspected nature and location of the planet, which has been the subject of an intense international search ever since Batygin and Brown's 2016 announcement.

The first, titled "Orbital Clustering in the Distant Solar System," was published in The Astronomical Journal on January 22. The Planet Nine hypothesis is founded on evidence suggesting that the clustering of objects in the Kuiper Belt, a field of icy bodies that lies beyond Neptune, is influenced by the gravitational tugs of an unseen planet. It has been an open question as to whether that clustering is indeed occurring, or whether it is an artifact resulting from bias in how and where Kuiper Belt objects are observed.

To assess whether observational bias is behind the apparent clustering, Brown and Batygin developed a method to quantify the amount of bias in each individual observation, then calculated the probability that the clustering is spurious. That probability, they found, is around one in 500.

"Though this analysis does not say anything directly about whether Planet Nine is there, it does indicate that the hypothesis rests upon a solid foundation," says Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy.

The second paper is titled "The Planet Nine Hypothesis," and is an invited review that will be published in the next issue of Physics Reports. The paper provides thousands of new computer models of the dynamical evolution of the distant and offers updated insight into the nature of Planet Nine, including an estimate that it is smaller and closer to the sun than previously suspected. Based on the new models, Batygin and Brown—together with Fred Adams and Juliette Becker (BS '14) of the University of Michigan—concluded that Planet Nine has a mass of about five times that of the earth and has an orbital semimajor axis in the neighborhood of 400 astronomical units (AU), making it smaller and closer to the sun than previously suspected—and potentially brighter. Each astronomical unit is equivalent to the distance between the center of Earth and the center of the sun, or about 149.6 million kilometers.

"At five Earth masses, Planet Nine is likely to be very reminiscent of a typical extrasolar super-Earth," says Batygin, an assistant professor of planetary science and Van Nuys Page Scholar. Super-Earths are with a mass greater than Earth's, but substantially less than that of a gas giant. "It is the solar system's missing link of planet formation. Over the last decade, surveys of extrasolar planets have revealed that similar-sized planets are very common around other sun-like stars. Planet Nine is going to be the closest thing we will find to a window into the properties of a typical planet of our galaxy."

Batygin and Brown presented the first evidence that there might be a giant planet tracing a bizarre, highly elongated orbit through the outer solar system on January 20, 2016. That June, Brown and Batygin followed up with more details, including observational constraints on the planet's location along its orbit.

Over the next two years, they developed theoretical models of the planet that explained other known phenomena, such as why some Kuiper Belt objects have a perpendicular orbit with respect to the plane of the solar system. The resulting models increased their confidence in Planet Nine's existence.

After the initial announcement, astronomers around the world, including Brown and Batygin, began searching for observational evidence of the new planet. Although Brown and Batygin have always accepted the possibility that Planet Nine might not exist, they say that the more they examine the orbital dynamics of the solar system, the stronger the evidence supporting it seems.

"My favorite characteristic of the Planet Nine hypothesis is that it is observationally testable," Batygin says. "The prospect of one day seeing real images of Planet Nine is absolutely electrifying. Although finding Planet Nine astronomically is a great challenge, I'm very optimistic that we will image it within the next decade."


Explore further

The super-Earth that came home for dinner

More information: Konstantin Batygin et al, The planet nine hypothesis, Physics Reports (2019). DOI: 10.1016/j.physrep.2019.01.009

Michael E. Brown et al. Orbital Clustering in the Distant Solar System, The Astronomical Journal (2019). DOI: 10.3847/1538-3881/aaf051

Journal information: Astronomical Journal

Citation: More support for Planet Nine (2019, February 27) retrieved 18 July 2019 from https://phys.org/news/2019-02-planet.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
1286 shares

Feedback to editors

User comments

Feb 27, 2019
very cool.

Feb 27, 2019
In deed,
A sirius challenge...

Which canine should we name this planet after?

The lead astronomer turns to her junior & in a worried tone, asks.
"Where Wolf?"

Feb 27, 2019
very cool.

Indeed it is. However I am reserving opine for the moment.
And....
I think just "Planet Nine" is cool enough...

Feb 27, 2019
We're waiting...
And waiting...
And...waiting...

Feb 27, 2019
very cool.

Indeed it is. However I am reserving opine for the moment.
And....
I think just "Planet Nine" is cool enough...


Since there's a Planet 9 already (Neptune is its name), Planet X would be even better...if it even exists. Telescopic images or it's not there.


Feb 27, 2019
Many scientists have said it could just be a combination of many gravitational sources. But surely the math and the models would rule that out if they are so sure it exists. Luckily they're being smart enough to admit it may NOT exist. It vaccinates them against the embarrassment if it fails to appear in real life.

Feb 27, 2019
In deed,
A sirius challenge...

Which canine should we name this planet after?

The lead astronomer turns to her junior & in a worried tone, asks.
"Where Wolf?"

http://explosm.ne...cs/2188/

Feb 27, 2019
Planet Nine has a mass of about five times that of the earth and has an orbital semimajor axis in the neighborhood of 400 astronomical units (AU)


Wrong, it simply does not exist. Anything that big and close would have been found by NASA's WISE mission or many of the subsequent surveys unless it is the most bizarrely dark object in the solar system.

Think of it this way, asteriod Farfarout is ~140 AU away with two lobes, each of them between 6 and 9 miles (10-15 km) wide. It is hard to imagine an object perhaps a thousand times bigger is hiding less than 3 times further away. For comparison, the diameter of Neptune is about 30,000 miles.

https://www.popul...-object/

Feb 27, 2019
Myself? I would bet the source of regular attraction (or, at least a portion of the disruptive influence) will turn out to be a small but massive planetoid of exotic elements. Captured from Interstellar Space, within the last few billion years.

"Out. out! Damn Spot!
Who forgot to walk the dog?"

Feb 27, 2019
Many scientists have said it could just be a combination of many gravitational sources. But surely the math and the models would rule that out if they are so sure it exists. Luckily they're being smart enough to admit it may NOT exist. It vaccinates them against the embarrassment if it fails to appear in real life.
says JamesG

LOL Yes, proceeding on the side of caution, it is.

Feb 27, 2019
The search for planet eleven

We have found planet nine, it is Pluto
we have found planet ten, its Eris
it is planet eleven we have yet to find
as
when we find this icy planet
no bigger
than Planet Pluto
so
when we find our eleventh plant
no bigger than our thumb
planetesimaly speaking
we
can proudly declare
Here is our eleventh icy planet

Feb 27, 2019
400 AU is simply the minimum required distance to explain said data, because the object could have a massive orbit going from 400 AU to 1200 AU, and if it was closer to 1200 AU - that and some composition (non-reflecting) would explain why we have not seen any indication of it. There is a difficult way of conclusively implying its existence; we precisely measure wobbles in the Sunand see if there are any unaccounted wobbles as we filter the known planets; the question is would we have sufficient resolution to detect a wobble for a super earth at 1200 AU; maybe not.

Feb 27, 2019
The Sumerian map of the galaxy has a planet 9 with an elliptical orbit around the sun. Planet 9 orbit was thousands of years. the drawings can be found on cuneiform texts on clay tablets in museums

Feb 27, 2019
"Planet 9" ? I thought planet 9 was Neptune, and Pluto was planet 10. Maybe they are talking about a different system?

Feb 27, 2019
"Planet Nine" Every time I see that name, I immediately think of "Plan 9 From Outer Space".

Feb 27, 2019
Planet 9 is Pluto. Go back to Grade School. If there is another planet to be found it will be the tenth planet, or Planet X

Feb 27, 2019
Planet Nine has a mass of about five times that of the earth and has an orbital semimajor axis in the neighborhood of 400 astronomical units (AU)


Wrong, it simply does not exist. Anything that big and close would have been found by NASA's WISE mission or many of the subsequent surveys unless it is the most bizarrely dark object in the solar system.

Think of it this way, asteriod Farfarout is ~140 AU away with two lobes, each of them between 6 and 9 miles (10-15 km) wide. It is hard to imagine an object perhaps a thousand times bigger is hiding less than 3 times further away. For comparison, the diameter of Neptune is about 30,000 miles.

https://www.popul...-object/


Yeah, I'm thinking that if this object exists, it must have an extremely low albedo.

Feb 27, 2019
No matter the stuporstitious claims by the wooloons...

The distances discussed are freklin' farandaway from the only light source.

It took the development of increasingly sophisticated telescopes in the 18th, 19th & 20th Centuries to begin to get an inkling that there was anything out there past Saturn. & then confirm those sightings.

I mean, the last several centuries of scientific advancement have been very unfair to astrologers. biblecoders spiritualists & all the other woolunatic cults.

^ no matter their "evidence"? The Sun does not get turned off at night!.

Feb 28, 2019
The search for planet eleven

We have found planet nine, it is Pluto
we have found planet ten, its Eris
it is planet eleven we have yet to find
as
when we find this icy planet
no bigger
than Planet Pluto
so
when we find our eleventh plant
no bigger than our thumb
planetesimaly speaking
we
can proudly declare
Here is our eleventh icy planet
says granville

Personally, I like the idea of a Planet Nine; planets 10 and 11 not so much. I think that 9 is a lucky number as far as planets go, so they say. We will not get to travel there, so forget about buying tickets.

Oh, and I report abusive, spam and offensive comments, like the one below.

Feb 28, 2019
The Sumerian map of the galaxy has a planet 9 with an elliptical orbit around the sun. Planet 9 orbit was thousands of years. the drawings can be found on cuneiform texts on clay tablets in museums
says short-wave

Yes, they were ahead of their time, those Sumerians. Living near the confluence of 2 rivers does that.

Feb 28, 2019
My naive take from an astrobiology interest is that the series of decreasing uncertainty in the works as well as the absence of competitive alternatives is promising, and that the new mass, source and disk estimates are exciting despite the degeneracies and other uncertainties. The mass estimate is the most common superEarth, the remaining plausible pathway is an endogenous scattered disk planet and the disk tilt is now uncoupled from P9 and so correlates better with other systems as well.

The most interesting paper to me is the updated likelihood model with the 0.2 % likelihood for random null, and obviously as per above the detail update in the review paper. As trivia the yet to be integrated Far Out and FarFarOut KBOs makes the Swedish in me chuckle: "Far" := Father and FarFar := Grandfather (so the pattern is "farfars far", "farfars farfar", "farfars farfars far" and so on).

Feb 28, 2019
More here from the 1st author: http://www.findpl...ess.html , http://www.findpl...ies.html , http://www.findpl...-2x.html .

Many scientists have said it could just be a combination of many gravitational sources.


It works in principle, since a method to estimate gravitational influence from planets is to smear them out along their orbit. But that is less likely when you do the modeling, since a debris disk is hard to form and hard to keep robust.

Anything that big and close would have been found by NASA's WISE mission


Of course it would not, or the papers would not be interesting for many. WiSE exclude but a small region of limited parameter space where P9 can hide, see the 2nd link above for a simple figure of exclusion criteria.

- tbctd -

Feb 28, 2019
-ctd-

The most likely prior is that the eccentric planet is close to aphelion where it spends most time in its orbit.

From the text of the 3d link: "... if Planet Nine is smaller, does that mean it's harder to find with a telescope? Counterintuitively, it's the opposite. The smaller distance from the sun more than makes up for the diminished surface area. Indeed, if we make naive baseline assumptions about P9's albedo and adopt the interpolated exoplanet mass-radius relation to estimate P9's size, Planet Nine turns out to be about one magnitude brighter than we previously thought. Annoyingly, though, the aphelion is very close to (in?) the galactic plane, where confusion due to background stars can readily impede detection. Still, unless we are unlucky and P9 is unexpectedly small and/or dark, it should be within the reach of LSST and comparable telescopes like Subaru. The good news is that in the case of Planet Nine hypothesis, time truly will tell."

- tbctd -

Feb 28, 2019
- ctd -

And from its comments: "... Should we expect, as you say, that "time truly will tell" soon-ish?" "... By soon-ish, I would guess about 5-10yrs."

there's a Planet 9 already

Planet 9 is Pluto.

Sumerian map of the galaxy has a planet 9


All irrelevant, planets outside Saturn (the 6th planet) had to be found by telescopes and if Ceres is not an astronomical planet (but a differentiated astrophysical one) Pluto and the other large KBOs are no longer either. Planets are not only qualitatively tied to dominating their neighborhood at the end of accretion, they are also robust phenomena as mature system planets show similar clearing. This is an old and void battlefield.

Feb 28, 2019
Well Ceres is massive enough to form the usual lumpy sphere.

In my opinion, that at least qualifies it to be listed as a dwarf planet.

I would of thought that the wanna-be-a-conquistador, would be Cortez & the Pizarro Brothers?

Would have leaped onto my speculation that the gravity mass waytohell&gone might be a captured Interstellar planetoid or asteroid of extremely dense exotic elements.

Too small & dark to be seen even with sophisticate instruments.

Opportunity knocking, boys.
Drop the bong & video-game controller & answer the damn door!

If that is a reasonable object de'art? It would be worth more than the Asteroid Belt...

Just saying. Don't come whining to me when it is claimed by Bolivia or Ceylon,Kenya or Tonga, Iran or Ecuador.
You had your chance & blew it out your pipe lollygagging on your Mommy's couch.

Feb 28, 2019
No matter the stuporstitious claims by the wooloons...

The distances discussed are freklin' farandaway from the ONLY LIGHT SOURCE.

It took the development of increasingly sophisticated telescopes in the 18th, 19th & 20th Centuries to begin to get an inkling that there was anything out there past Saturn. & then confirm those sightings.

...BRAY...BRAY..BRAY...

^ no matter their "evidence"? The Sun does not get turned off at night!.

The rrwillsj idiot, brays.

There are some, who say so little, while saying so much, but you have outdone them all by saying less than nothing.
There is an interesting documentary out on the web, of how NASA located Ultima Thule, by imaging it as it passed in front of a distant star. The sun isn't the only light source.

Feb 28, 2019
Shouldn't this be called a comet instead of planet, if finally discovered?

Mar 01, 2019
- ctd -

And from its comments: "... Should we expect, as you say, that "time truly will tell" soon-ish?" "... By soon-ish, I would guess about 5-10yrs."

there's a Planet 9 already


This is an old and void battlefield.


No, sorry, the debate goes on.

Mar 01, 2019
"Planet 9" ? I thought planet 9 was Neptune, and Pluto was planet 10.


You're right. Ceres is geophysically a planet also and is Planet 5.


Mar 01, 2019
"Planet 9" ? I thought planet 9 was Neptune, and Pluto was planet 10.


And then Haumea, Makemake and Eris are planets 11, 12 and 13. Mike Brown is co-discoverer of two, possibly three planets and he's probably got chronic heartburn because the IAU won't give him credit for co-discovering major planets.


Mar 01, 2019
"Planet 9" ? I thought planet 9 was Neptune, and Pluto was planet 10.


You're right. Ceres is geophysically a planet also and is Planet 5.


I always think some funky thoughts about why they could possibly be "hiding" Ceres. Maybe it contains a secret base? :P

It did look like a few months ago they were going to overturn the fiasco that was the Pluto reclassification. So much silliness.

Mar 01, 2019
well, after filtering out all the praying noise?
I got through auntieorals rant to discover. the irrelevant to this discussion, fact that the Sun is not the only source of light.
Just only in this System for the purpose of reflection.

After posting such a major revelation?
he/she/it had to go lie down & sooth it's racing heart. A strain for such a delicate creature.

Mar 01, 2019
It took the development of increasingly sophisticated telescopes in the 18th, 19th & 20th Centuries to begin to get an inkling that there was anything out there past Saturn.


I would add that mathematics were used to trigger and focus a search for Neptune which was discovered essentially right where Urbain Le Verrier.predicted it would be. It is a good story if you are unfamiliar with it.

https://en.wikipe.../Neptune

Mar 01, 2019
antidumbassicle: "The sun isn't the only light source."

You are the dimmest of the dim bulbs and have shedded no light on anything. You are also a Scumbag Denier with no credibility whatsoever. How much is Putin paying you?

Mar 01, 2019
Me: Anything that big and close would have been found by NASA's WISE mission

Tbctd: Of course it would not, or the papers would not be interesting for many. WiSE exclude but a small region of limited parameter space where P9 can hide, see the 2nd link above for a simple figure of exclusion criteria.

Me: I disagree. The chart displayed in your link shows the WISE detection limit as a flat line at 10^2 Earth masses, invariant with distance. That is obviously incorrect.:

http://www.findpl...ies.html

More than three (3) years after its announcement, with nothing found, I would estimate the chances of Planet 9 currently existing where Brown says it is at less than 5%.

Mar 01, 2019
oi, arcmetal "So much silliness"

Welcome to the Internet Zoo monkey cages. Here, we loydly screech vicious insults while flinging our excrement at one another!

You want "Silly"?
Go over to the Grammarian Lizard's Display & partake of the fabulously colorful domination posturing.
As they debate
"Oxford Commas".

This was what actually caused the extinction of the dinosaurs. Ennui... At a rate of mental fossilization to result in coprolites!
Coprolites DBA auntieoral.
Having to listen to the endless droning pipes of the grammarians? Bored the dinosaurs to death.

The Avians were more fortunate.
They were able to flee in haste.
As if they were being chased by the proverbial "bats out of hell. Now DBA sillyegghead.

Mar 01, 2019
"Planet 9" ? I thought planet 9 was Neptune, and Pluto was planet 10. Maybe they are talking about a different system?


and? they believed in a multiplicity of gods as well.

Mar 30, 2019
Astronomer Forbes found three orbital parameters of a planet in the outer solar system in 1880 by examining long period comet aphelion:
https://www.forbe...bfb33f16
Our Obsession With Hidden Planets Didn't Start With Planet Nine

No explanation of why his orbital parameters are not valid. We found a body with similar parameters in the 2002-2004 time frame and dubbed it Vulcan. We have an estimate of its mass and all six orbital parameters. Perhaps the search for planet Nine has been completed 15 years ago:
http://barry.warm...led.html

Mar 31, 2019
The UOA astronomers predict the orbital inclination is either 18 or 48 degrees. Vulcan's is 48.44 +/- 0.26 degrees. The Spanish stonomers say planet Nine's semimajor is in e 300-400 AU. Range Forbe's planet is ~300AU. Vulcan's semi-major is 292.2 AU. Vulcan forms comet swarms in 3:2 Resonate orbits that can pass thru the inner solar system. Thus we can verify Vulcan's 4969.0 year period from paleoclimatlogical data and the 3:2 Resonate orbit of CR105. It is 4969.3 years. Vulcan (comets) indirectly causes Earth's climate to change. Perhaps IRAS 1732+239 really is Planet Nine.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more