Caltech: Researchers Find Evidence of a 'Real' Ninth Planet

[Fiery Phoenix]

This has been all over the news this morning. As of right now, the discovery remains indirect, but all signs point to it being a strong evidence. Here's Caltech's news release:

Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system. The object, which the researchers have nicknamed Planet Nine, has a mass about 10 times that of Earth and orbits about 20 times farther from the sun on average than does Neptune (which orbits the sun at an average distance of 2.8 billion miles). In fact, it would take this new planet between 10,000 and 20,000 years to make just one full orbit around the sun.

...

Brown notes that the putative ninth planet—at 5,000 times the mass of Pluto—is sufficiently large that there should be no debate about whether it is a true planet. Unlike the class of smaller objects now known as dwarf planets, Planet Nine gravitationally dominates its neighborhood of the solar system. In fact, it dominates a region larger than any of the other known planets—a fact that Brown says makes it "the most planet-y of the planets in the whole solar system."

Also:

And indeed Planet Nine's existence helps explain more than just the alignment of the distant Kuiper Belt objects. It also provides an explanation for the mysterious orbits that two of them trace. The first of those objects, dubbed Sedna, was discovered by Brown in 2003. Unlike standard-variety Kuiper Belt objects, which get gravitationally "kicked out" by Neptune and then return back to it, Sedna never gets very close to Neptune. A second object like Sedna, known as 2012 VP113, was announced by Trujillo and Shepherd in 2014. Batygin and Brown found that the presence of Planet Nine in its proposed orbit naturally produces Sedna-like objects by taking a standard Kuiper Belt object and slowly pulling it away into an orbit less connected to Neptune.

Much more at the link here:

http://www.caltech.edu/news/caltech-...h-planet-49523

For those of you wanting to read the original paper (which is as of yet unpublished as I understand), it can be found here:

http://iopscience.iop.org/article/10...-6256/151/2/22

So...!

[jokergirl]

I guess the Nibiru people are going wild.

[Fiery Phoenix]

According to my calculations based on the article, the orbital distance is between 464 and 736 AU, which translates into an average of 600 AU.

[Centaur]

The word planet comes from the pre-telescopic ancient Greek term "astēr planētēs" meaning "wandering star" which referred to the bright points of light in the sky which appeared to move relative to most of the others. Since this conjectured object cannot be seen by naked eyes, then by the original sense of the term it is not a planet. Of course, neither is the Earth.

[Swift]

I think some of the media coverage of this is starting to over-reach. For example, this from Laboratory Equipment magazine:

A far-off ninth planet, still unseen, has been identified by Caltech researchers.

To me, until it is actually seen and observed enough to confirm an orbit, it has not been identified. The abstract of the actual paper, which is at the second link Fiery Phoenix gave, makes it clear that the authors are proposing this as a hypothesis, and are not claiming either its identification or discovery.

I am not belittling the actual work. If shown to be true, this will be a terrific discovery. We just shouldn't put the sky chariot too far in front of the horses.

[Fiery Phoenix]

To me, until it is actually seen and observed enough to confirm an orbit, it has not been identified. The abstract of the actual paper, which is at the second link Fiery Phoenix gave, makes it clear that the authors are proposing this as a hypothesis, and are not claiming either its identification or discovery.

I am not belittling the actual work. If shown to be true, this will be a terrific discovery. We just shouldn't put the sky chariot too far in front of the horses.

I agree. I imagine the paper will lead many other astronomers around the globe to point their telescopes to that direction, giving way to a possible confirmation. Apparently the planet is 'just small enough' for survey observatories like WISE to miss it.

Until then, I remain cautiously excited. (P.S. It appears there's already a Wiki entry on this planet.)

[Swift]

And just to add to my previous post, this headline from R&D magazine is just stupid:

Pluto Killer Announces Evidence of Ninth Planet

In 2006 Pluto took a hard hit. Not literally, but figuratively. That year, the International Astronomical Union came up with a new definition of the word “planet.” The move demoted Pluto to a “dwarf planet.”

Prof. Mike Brown, of the California Institute of Technology, was the man behind the research that led to the decision. And now he’s one of the men behind the announcement that a new ninth planet may be lurking beyond Neptune.

"Pluto Killer"? Really? Are the editors of R&D magazine planning to hold their breath until Pluto is made a planet again.

[Don Alexander]

Swift, Mike Brown's Twitter handle is @plutokiller...

https://twitter.com/plutokiller?lang=en

Anyway, I propose to name this planet, if it turns out to be real "Yuggoth on the Rim"!!

[PetersCreek]

...and let the pun games begin: Planet 9 From Outer Space

[Drummer62]

Fascinating discovery, provided it's confirmed.

What puzzles me is how this object (and at 10 times Earth mass it's not exactly very small) could have been missed so far?
I don't understand much about the organization and mechanics of astronomical observations and would be grateful if a professional could shed some light on this.

[jokergirl]

Would it be possible to calculate the approximate orbital position from the perturbances and turn a telescope that way? Even so, it'd be hard to spot, I bet, and the math seems seriously complicated, but still?

[Fiery Phoenix]

Would it be possible to calculate the approximate orbital position from the perturbances and turn a telescope that way? Even so, it'd be hard to spot, I bet, and the math seems seriously complicated, but still?

They seem to have a general target direction/orbital zone, but nothing exact. See here:

http://www.sciencemag.org/news/2016/...n-solar-system

[Don Alexander]

Let me try an analogy.

You're standing outside, looking toward a wall. You detect several splotches on the wall, which are quite grouped. You come to the conclusion: "Seems likely there is a paintball player behind me, aiming at the wall."

But it might not be a paintball player at all, the grouping could be by chance (reasonably unlikely, but hardly impossible), or perhaps caused by some other effect. The paintball explanation fits the data, yes, but it's hardly rock solid.

And in terms of the location of the paintball player? Well, "somewhere behind you." Oh, and he's TINY. And looks like a leaf. In front of an entire forest.

I haven't seen any values for rough observable magnitudes so far. My verrrry rough shot-in-the-dark guesstimate would be ~25 mag in the optical. Perhaps even several fainter? At this distance, it would essentially be a point source, and while the technology exists to detect it, you have literally millions upon millions of other sources that will confuse you. At these depths, you get loads of tiny galaxies that are all also essentially point sources. the great distance of ~500 - 1000 AU implies that both orbital motion as well as parallax will be smaller than for any known Solar System object.

It looks like they will start looking with Subaru's HyperSuprimeCam, but even this grand magnifying glass hardly puts a dent into the haystack that's hiding your needle...

[slang]

Fascinating discovery, provided it's confirmed.

What puzzles me is how this object (and at 10 times Earth mass it's not exactly very small) could have been missed so far?
I don't understand much about the organization and mechanics of astronomical observations and would be grateful if a professional could shed some light on this.

I seem to remember that in one of the gazillion Planet X topics a study was shown that put limits on what size of planet could still be undiscovered within some named orbital distance. Perhaps someone remembers better. This one would be 20 times further out than Neptune? Perhaps we should tell New Horizons to start looking in 190 years.

[Fiery Phoenix]

It looks like they will start looking with Subaru's HyperSuprimeCam, but even this grand magnifying glass hardly puts a dent into the haystack that's hiding your needle...

I suspect this is part of the reason Mike Brown estimates ~5 years before a detection can occur. It's a tough task, but nothing we haven't done before.

I seem to remember that in one of the gazillion Planet X topics a study was shown that put limits on what size of planet could still be undiscovered within some named orbital distance. Perhaps someone remembers better. This one would be 20 times further out than Neptune? Perhaps we should tell New Horizons to start looking in 190 years.

You may be thinking of the 2013 study which concluded that planets the size of Neptune Saturn or larger cannot exist within 10,000 AU of the Sun (as per WISE's observations). Since this potential planet is below this threshold, the current thinking is that WISE simply missed it.

[Don Alexander]

@Fiery Phoenix: It was planets the size of Saturn. Big difference.

Furthermore, WISE was an all-sky survey, it did not miss anything unless it was too faint for detection (which can be due to an object being extremely cold).

[Fiery Phoenix]

Apologies. Yes, I meant to say Saturn-sized. Thanks, Don!

[Don Alexander]

The whole "it might take 5 years" thing makes me wonder if LSST has a chance. Not sure when that will have first light...

[Fiery Phoenix]

The whole "it might take 5 years" thing makes me wonder if LSST has a chance. Not sure when that will have first light...

Well, apparently Brown and co. have already reserved telescope time with Subaru. That should hopefully suffice for the time being.

[Drummer62]

Thanks, Don Alexander, for your analogy.
I understand that the object is tiny compared to its distance. I just thought (wrongly) that our observational capabilities were advanced enough to routinely catch objects of that size in our own solar system.

As far as "Planet X" or "Nibiru" is concerned I just read a wikipedia article about it.
Let it be known that I don't believe in any doomsday conspiracies whatsoever (humans do a pretty good job of destroying our planet all by ourselves).

One of the arguments to reject the Nibiru myth was: "A planet such as Nibiru would create noticeable effects in the orbits of the outer planets." (from that wiki article, section "Scientific rejection").
That argument always made perfect sense to me. However, now not so much any more. Does not the discovery of "Planet 9" (if confirmed) falsify that argument? If we have missed this object, what else did we miss?

I am not trying to resurrect the Nibiru myth and I am not advocating any conspiracies associated with it. I am only interested in the validity of the original scientific rejection of Nibiru in the light of the new discovery (if confirmed).

ETA: According to Nancy Lieder (the somewhat disturbed original promoter of Nibiru) it was supposed to be "roughly four times the size of the Earth", significantly smaller than the proposed Planet 9.

[Don Alexander]

I just thought (wrongly) that our observational capabilities were advanced enough to routinely catch objects of that size in our own solar system.

The problem here is aperature cost. Finding TNOs implies blind searches - even if you stay in the ecliptic, you have a complete band of sky to search. TNOs are almost always fainter than 20th magnitude. If you want to find any, you need to go wide, not deep, which implies quite dedicated telescopes, and such telescopes are small, and can't go deeper than 22nd, maybe 23rd magnitude. You are not going to get time at Big Glass with pencil-beam optics to just randomly stare somewhere multiple times in the hopes of finding something.

I am not trying to resurrect the Nibiru myth and I am not advocating any conspiracies associated with it. I am only interested in the validity of the original scientific rejection of Nibiru in the light of the new discovery (if confirmed).

P9, if real, lies in an orbit with even perihelion at ~200 AU. This is much further away than even Neptune/Pluto. A planet of P9's size would not measurably perturb the orbits of objects closer in than the Kuiper Belt.

[efanton]

I wonder if the New Horizons mission would possibly be able to get a better view. Of course with such a huge orbit involved it would mean that a bit of luck would be required as both would have to be on the same side of the sun.

[Drummer62]

The problem here is aperature cost. Finding TNOs implies blind searches - even if you stay in the ecliptic, you have a complete band of sky to search. TNOs are almost always fainter than 20th magnitude. If you want to find any, you need to go wide, not deep, which implies quite dedicated telescopes, and such telescopes are small, and can't go deeper than 22nd, maybe 23rd magnitude. You are not going to get time at Big Glass with pencil-beam optics to just randomly stare somewhere multiple times in the hopes of finding something.

P9, if real, lies in an orbit with even perihelion at ~200 AU. This is much further away than even Neptune/Pluto. A planet of P9's size would not measurably perturb the orbits of objects closer in than the Kuiper Belt.

Thanks again, Don Alexander, both explanations make sense to me.

[Jens]

Also, I don't know if anyone is saying that an object with the orbital characteristics doesn't exist, but rather are saying that there is no evidence that it does, so therefore no reason to think it it exists anymore that an almost infinite number of other possible bodies. So it's really the claim that it exists that people dispute.

[antoniseb]

I wonder if the New Horizons mission would possibly be able to get a better view. Of course with such a huge orbit involved it would mean that a bit of luck would be required as both would have to be on the same side of the sun.

New Horizons is about 40 AU out, and has a fairly small diameter camera. If this thing is 700 AU out, that 5% closer that NH might have won't help much.

[Fiery Phoenix]

Yeah, New Horizons unfortunately doesn't have much chance here. We also don't know the orbital position of this potential planet.

[efanton]

New Horizons is about 40 AU out, and has a fairly small diameter camera. If this thing is 700 AU out, that 5% closer that NH might have won't help much.

I tend to agree with you, but a terrestrial telescope has the atmosphere to deal with.

At those distances I would imagine it would have to have the albedo of a 100 watt bulb to see it with any telescope we currently have.

[Fiery Phoenix]

I tend to agree with you, but a terrestrial telescope has the atmosphere to deal with.

Subaru is supposed to be able to detect it, assuming it is where/what we think it is. But it still won't be easy!

[jokergirl]

They seem to have a general target direction/orbital zone, but nothing exact. See here:

http://www.sciencemag.org/news/2016/...n-solar-system

Thanks. That's a fairly big chunk of the proposed orbit still. Maybe they can narrow it down if they find more of those tell-tale perturbances. Which I suspect they now will be looking for, to either prove or disprove what we know so far.

[Swift]

Calling it "Planet X" seems wrong to me. First, if I understand correctly, when the idea of a then 10th planet was suggested, Pluto was still the 9th, and X stood for 10 (Roman numeral) and X as in unknown. But it would be the ninth planet now, not 10, and the term "Planet X" is too connected with Nibiru and Nancy Lieder and all that nonsense.

Somewhere I've also seen it referred to as "Planet 9" and that works fine for me.