Planet 9.

[StormAurora]

Recent news stated that due to unusual data recorded in the Kuiper belt, that it may possibly be due to a large planet or failed star orbiting the sun.

What do you think of this news? Could it be possible?

Any idea what the impact may be on the inner planets, if this object came close to the Sun?

[ronin]

This keeps appearing and at this time no evidence for such an object.

What does "unusual data" mean? SInce we have no or very, very little idea or daata on the Kuiper belt I would say that just about anything is unusual. So far every prediction on just about everything has been wrong. All satellites were expected to be dead dormant bodies, and the moons of Jupiter and Saturn proved that to be utterly wrong. Stars were initially expected to not have planets, that changed to ecery star now has and is expected to have planets. All these planets if they existed were expected to follow ours systems in structure - guess what totally wrong again.

So far the predictions and ideas have been sort of wrong and wrong in a big way.

Another aspect is if we had a plant orbiting at I think it is supposed to be 20,000 year period then every 20,000 years I would expect there should be a comet bombardment of the inner planets. And there is no periodic bombardment in evidence.

Any idea what the impact may be on the inner planets, if this object came close to the Sun? 

That would be a change of orbit so as the arguement is that it is a "unknown" planet then it is in a stable orbit, and so would by definition not come close to the sun, it would remain in it's defined orbit.

If it were a failed star then it would have a large radio signature, Jupiter and Saturn both have, so one of the many radio dishes would I suggest have found such an object years ago. There have been a number of radio surveys of the sky.

I have had the impression for some time that the approach is "Make a big headline, get funding." in too much of the astronomy field now. Bet they were really upset when Pluto was demoted, as then we had 9 planets so a "mystery" one would be 10, or X in roman numerals.

[michael.h.f.wilkinson]

Actually, there is some interesting data published in serious journals (including Nature). As I recall, the on orbital parameters of a number of Kuiper Belt objects are so similar that there must be something favouring that particular set, according to a team of astronomers. The object would be in a very, very wide, eccentric orbit (aphelion 1200AU, perihelion 200AU), and extremely dim (roughly the size of Neptune). There was a more recent paper claiming the inclination of the sun's axis of rotation with respect to the ecliptic could also be explained by the same object. They are trying to narrow down the possible position of the object. From earlier surveys, a Jupiter-sized object, and certainly a failed star (brown dwarf) can be ruled out to 26,000 AU, but a Neptune-sized object at 700 AU might well go undetected in the surveys. 

 

So it is certainly possible that such an object lurks there. More research is needed before we have proof.

[Knight of Clear Skies]

The current search is a based on a good hypothesis - something has pulled these distant these distant TNOs (Trans-Neptunian Objects) into eccentric and related orbits. (By the way, they aren't KBOs as their orbits take them far beyond the KuiperBelt.)

But hypothesis are for considering and testing, not for believing. The two big unknown quantities at the moment are:

- Is Planet Nine really the best explanation for this orbital clustering, or could it be caused by something else we haven't thought of?

- How strong is this clustering effect really? Could it be due to observational bias?

Brown and Batygin have some good articles on their site here, covering the evidence for Planet Nine, some reasons why it might not exist and where it could be hiding. I fully support the search - even if it draws a blank we'll learn more about the outer reaches of the solar system.

[newbie alert]

Pluto is on a strange orbit itself,so something must be affecting its obital plane..new horizons is on its way to a kbo, eris i think..so hopefully it can opperate its cameras and send a signal back..

Dont think we are advanced enough to see whats there yet but things move on so fast hopefully we will understand soon enough..

[Ravenous]

2 hours ago, newbie alert said:

Pluto is on a strange orbit itself,so something must be affecting its obital plane..new horizons is on its way to a kbo, eris i think..so hopefully it can opperate its cameras and send a signal back..

 

Pluto does have a funny inclined orbit, but this has been put down to the Kozai mechanism - not undiscovered planets. In other words Neptune's influence didn't just cause Pluto's elliptical orbit, it also caused the inclination.

There are other smaller objects in pluto-like orbits, several of them inclined.  You'll often see these called "Plutinos".

[StormAurora]

Thanks for the interesting and thought provoking replies. It really is an exciting time to be alive!

[SilverAstro]

8 hours ago, Knight of Clear Skies said:

The current search is a based on a good hypothesis - something has pulled these distant these distant TNOs (Trans-Neptunian Objects) into eccentric and related orbits.

 That was the pic I was looking for

The beeb did a couple of progs about it last year, a very good one was Sky@Night, sadly no londer available ? on iPlayer when I looked just now, but 'tube to the rescue :-

http://www.dailymotion.com/video/x3tb0yb

 

[Ravenous]

By the way there was some discussion perhaps a year ago, about using New Horizons as a source of information.

If its telemetry can be measured accurately enough for a decade or so, slight discrepancies in velocity could indicate whether this "Planet 9" exists at all.

Note this isn't about using the probe's cameras to image such a planet.  The distance would be huge, so the cameras probably aren't any good for that.