Woops! Eve has escaped it seems...

[FITorion]

Solar system formation is a chaotic thing. Most stars form in pairs or more. We've seen bigger gas giants around other stars. To call this a failed star is to call Jupiter a failed star.

True at some point they get so large that they are more star like than gas giant like but I don't think this quite qualifies.

It probably got ejected from its system during formation. As such things don't really glow that much... it's hard for us to tell just how much stuff is wandering around interstellar space.

[nuclearpower13]

Scientist have estimated that there are more of these Rogue Planets in our Galaxy than there are planets like ours orbiting there host star. The thing that fascinates me is that these planets at a very "young" age are flung out of there of there home system by a gravitational conflict with another object in which it accelerates to escape velocity and is ejected out of the home system doomed to wander the galaxy forever. I've been thinking a bit about something. Sedna has one of the most eccentric orbits in our sol system. Is it possible Sedna was on its way out but was slowed down enough by the sun gravitational pull that it reentered orbit around the sun?

[Geschosskopf]

To call this a failed star is to call Jupiter a failed star.

Isn't it? As you say, single stars like ours are the minority; there are way more binary+ systems. The only difference between a gas giant planet and a small star is one of degree, not fundamentals. Pile up a "small" amount of stuff and you get a gas giant. Pile up a bit more and you get a brown dwarf, and so on up the scale. They're all made of the same stuff, all accumulated by the same processes.

Check out this related article to the OP:

http://www.sciencedaily.com/releases/2013/10/131009152944.htm

[lockpicker]

Who knows? Maybe one of these planets one day will be caught at our solar system.

[Mode1Bravo]

Thats incredible, Didn't know planets could do that.

Really though, is there such thing as free floating in space?

Afaik, No matter where, You will always be orbiting something.

Well, all things in a galaxy orbits around its center, so it technically doesn't need a "Sun"/Star to orbit around.

[lajoswinkler]

Solar system formation is a chaotic thing. Most stars form in pairs or more. We've seen bigger gas giants around other stars. To call this a failed star is to call Jupiter a failed star.

True at some point they get so large that they are more star like than gas giant like but I don't think this quite qualifies.

It probably got ejected from its system during formation. As such things don't really glow that much... it's hard for us to tell just how much stuff is wandering around interstellar space.

Jupiter is a less failed star than this new lone planet is. Jupiter was formed around an object that was already a protostar. This planet is alone. It clumped from a mass of gas and dust (perhaps gas only, irrelevant) and it seems it never orbited anything, unless it was ejected from a system, which is unlikely.

[vetrox]

A quote from the op link in reply to the "its a failed star" comment

PSO J318.5-22 belongs to a collection of young stars called the Beta Pictoris moving group that formed about 12 million years ago. In fact, the eponymous star of the group, Beta Pictoris, has a young gas-giant planet in orbit around it. PSO J318.5-22 is even lower in mass than the Beta Pictoris planet and probably formed in a different fashion

[softweir]

Just to note that this sort of stuff is Real_World Science, and as such belongs in The Science Labs. SO: Over it goes!

[-Velocity-]

Jupiter is a less failed star than this new lone planet is. Jupiter was formed around an object that was already a protostar. This planet is alone. It clumped from a mass of gas and dust (perhaps gas only, irrelevant) and it seems it never orbited anything, unless it was ejected from a system, which is unlikely.

Why do you find it unlikely to have been ejected from a system?

[frizzank]

Jupiter is a less failed star than this new lone planet is. Jupiter was formed around an object that was already a protostar. This planet is alone.

Something as massive as a 6x Jupiter would not be alone, it most likely has friends in its vivacity that we have not been able to detect yet.

It clumped from a mass of gas and dust (perhaps gas only, irrelevant) and it seems it never orbited anything, unless it was ejected from a system, which is unlikely.

All they know is that its there, the why and how are still up for discovery. It is just as likely that it got ejected from its parent star, considering how young they think it is.

[lajoswinkler]

Why do you find it unlikely to have been ejected from a system?

Because the lighter the object is, the greater the chance is it was made in a neat way, in the disc around the protostar. Massive objects tend up forming a binary star system and with such great forces between them, instability is expected early in the formation of the system.

This is a tiny object, not even a brown dwarf.

It probably does have satellites around it.

It might have been ejected from a binary star system, though, but given the quantity and the dispersal of interstellar matter in the universe, I'd expect huge humbers of brown dwarfs and large gas giants that have failed to ignite, orbiting the galactic center. Maybe this is an example of it.

[drakesdoom]

Really guys? You disappoint me.

THAT'S NO MOON!

[-Velocity-]

Because the lighter the object is, the greater the chance is it was made in a neat way, in the disc around the protostar. Massive objects tend up forming a binary star system and with such great forces between them, instability is expected early in the formation of the system.

This is a tiny object, not even a brown dwarf.

It probably does have satellites around it.

It might have been ejected from a binary star system, though, but given the quantity and the dispersal of interstellar matter in the universe, I'd expect huge humbers of brown dwarfs and large gas giants that have failed to ignite, orbiting the galactic center. Maybe this is an example of it.

Ok, yea, I don't buy that at all. What is this thing, 5 Jupiter masses? How can five Jupiter masses by itself pull in enough interstellar gas to form by itself outside a protoplanetary disk? I suppose maybe it's possible, and they have found objects similar in size that they THINK might have formed by themselves (though astronomers were surprised and skeptical). So I don't think we can say it's unlikely that this is simply an ejected, giant planet. I'm not sure we really know enough about star formation and planet formation to say such a small object is "unlikely" to have been ejected, especially when the concept of objects weighing just a dozen Jupiters or less being able to form by themselves out of raw nebular material is so new and controversial to astronomy.

Also, I don't see how you can say it's unlikely for it to have any objects orbiting it; Jupiter, Saturn, Uranus, and Neptune all have nice little (or not so little) families of moons. As long as the close encounter that ejected the object wasn't TOO close, it ought to still have at least its innermost moons. And if it formed like a star, it is even more likely to have small bodies orbiting it.

Anyway, I'm just a little confused overall at what you're trying to say, in fact:

Why do you find it unlikely to have been ejected from a system?

Because the lighter the object is, the greater the chance is it was made in a neat way, in the disc around the protostar...

This is a tiny object, not even a brown dwarf.

If it formed in a disk around another star, it is an ejected object.

Edited October 12, 2013 by |Velocity|

[lajoswinkler]

Ok, yea, I don't buy that at all. What is this thing, 5 Jupiter masses? How can five Jupiter masses by itself pull in enough interstellar gas to form by itself outside a protoplanetary disk? I suppose maybe it's possible, and they have found objects similar in size that they THINK might have formed by themselves (though astronomers were surprised and skeptical). So I don't think we can say it's unlikely that this is simply an ejected, giant planet. I'm not sure we really know enough about star formation and planet formation to say such a small object is "unlikely" to have been ejected, especially when the concept of objects weighing just a dozen Jupiters or less being able to form by themselves out of raw nebular material is so new and controversial to astronomy.

Also, I don't see how you can say it's unlikely for it to have any objects orbiting it; Jupiter, Saturn, Uranus, and Neptune all have nice little (or not so little) families of moons. As long as the close encounter that ejected the object wasn't TOO close, it ought to still have at least its innermost moons. And if it formed like a star, it is even more likely to have small bodies orbiting it.

Anyway, I'm just a little confused overall at what you're trying to say, in fact:

If it formed in a disk around another star, it is an ejected object.

Why do you think that there could not exist ancient lighter objects (relative to average stars) that were made by a collapse of dust and gas? Too weak forces? All you need is enough time and gravity wins. You're talking about an already made 5x Jupiter mass attracting the material. I wasn't talking about that.

I see no reason why a smaller interstellar cloud couldn't collapse on its own and form an object not dense enough to start hydrogen-1 fusion. I admit it might be a problem with the amount time, but that would take some rather serious calculations to confirm.

Other than that, I can imagine whole tiny "nonsolar systems" that look like a gas giant satellite systems just because the center stuff never ignited and started glowing. Those would be very tiny systems with lots of ice because the center object never puffed it away. Sort like a stillborn system, frozen, dead and dark, with serious heat only the one trapped in the center of larger bodies.

I said it probably does have satellites.

[-Velocity-]

Why do you think that there could not exist ancient lighter objects (relative to average stars) that were made by a collapse of dust and gas? Too weak forces? All you need is enough time and gravity wins. You're talking about an already made 5x Jupiter mass attracting the material. I wasn't talking about that.

I see no reason why a smaller interstellar cloud couldn't collapse on its own and form an object not dense enough to start hydrogen-1 fusion. I admit it might be a problem with the amount time, but that would take some rather serious calculations to confirm.

Other than that, I can imagine whole tiny "nonsolar systems" that look like a gas giant satellite systems just because the center stuff never ignited and started glowing. Those would be very tiny systems with lots of ice because the center object never puffed it away. Sort like a stillborn system, frozen, dead and dark, with serious heat only the one trapped in the center of larger bodies.

I said it probably does have satellites.

Whoops then about the satellites... I have no idea how I could have read that so wrong, like three or four times in a row... goes to show you how much the brain speeds up reading by filling in expected words and meanings rather than just READING what's there..

Anyway, my point was just that I didn't feel we could say it's "unlikely" that this is an ejected object.

I do see a problem with interstellar gas clouds collapsing into very small objects, but I don't know at where the cutoff lies, and I don't think astronomers have an exact idea either. It would have to take a long time, in a non-turbulent cloud, that, for some reason, does not form any stars large enough to blow the rest of the gas and dust away before very small objects were allowed to form.

[magnemoe]

Why do you think that there could not exist ancient lighter objects (relative to average stars) that were made by a collapse of dust and gas? Too weak forces? All you need is enough time and gravity wins. You're talking about an already made 5x Jupiter mass attracting the material. I wasn't talking about that.

I see no reason why a smaller interstellar cloud couldn't collapse on its own and form an object not dense enough to start hydrogen-1 fusion. I admit it might be a problem with the amount time, but that would take some rather serious calculations to confirm.

Other than that, I can imagine whole tiny "nonsolar systems" that look like a gas giant satellite systems just because the center stuff never ignited and started glowing. Those would be very tiny systems with lots of ice because the center object never puffed it away. Sort like a stillborn system, frozen, dead and dark, with serious heat only the one trapped in the center of larger bodies.

I said it probably does have satellites.

Push from supernovas and gravity from other stars are probably the reason why interstellar gas collapses. perhaps escaped comets helps? Dull red stars are most common and brown dwarfs is belived to be even more so, makes some sense that even smaller objects are more common. Yes its probably some size who start to become less common again.

However they will be very hard to find, we only fond this as it's so new its still glowing.

Yes it could be ejected from an double star system, they are also common.

[lajoswinkler]

Who knows, maybe such bodies are the stuff behind dark matter. They don't emit light and their infrared and radiowaves are really weak. It is a bit scary to think about the possible huge number of such failed, stillborn systems out there, spinning in darkness. The view from the tiny planets would be creepy. Their parent body would be a completely black void in the sky. If the interstellar wind is powerful enough, it might cause auroras, but I doubt it.

[Will Fawkes]

Still a planet. A brown dwarf is large enough to fuse/have fused Deuterium, but small enough that hydrogen-hydrogen fusion is impossible. I forget the exact limits, but that is something on the order of 10-12 Jovian masses up to around 30 or so Jovian masses. Below that an no Deuterium Fusion, above that and it becomes a red dwarf as hydrogen-hydrogen fusion occurs.

Well the limits are, if i remember, a bit 'fuzzy' due to composition but I'd always heard something like twenty times jupiter being the lower limit for a red dwarf, and much below that you get into brown dwarf territory but you give a wider range so I'm differing to you on this one.

I'm more interested in the fact we found this thing when it emits no real visible light and would be so small seeing it on IR would probably be problimatic.

Interesting stuff.

[-Velocity-]

Who knows, maybe such bodies are the stuff behind dark matter. They don't emit light and their infrared and radiowaves are really weak. It is a bit scary to think about the possible huge number of such failed, stillborn systems out there, spinning in darkness. The view from the tiny planets would be creepy. Their parent body would be a completely black void in the sky. If the interstellar wind is powerful enough, it might cause auroras, but I doubt it.

Nope, whatever dark matter is, it is *not* primarily composed of MACHOs (Massive Compact Halo Objects). They have used gravitational microlensing to gauge the density of MACHOs, and the density is not high enough to account for the universe's missing gravitating matter. It appears that the majority of dark matter really is WIMPs (Weakly Interacting Massive Particles). Well, hopefully. I'd hate for dark matter to actually be composed of GIMPs (Gravitationally Interacting Massive Particles), because if they only interact with normal matter through gravitation, how the hell are we ever going to directly detect them? Maybe we could produce them in particle accelerator experiments and note their creation as mass or energy that apparently goes missing??

Edited October 15, 2013 by |Velocity|

[Dunbaratu]

I liked this bit:

"...has a mass only six times that of Jupiter"

Only? Surely a planet that is six times as heavy as Jupiter is a pretty damn big planet?

Big planet? yes. But small enough not to be a star. The "only" was referring to "We're calling it a planet because it's too small for a star.

[lajoswinkler]

Nope, whatever dark matter is, it is *not* primarily composed of MACHOs (Massive Compact Halo Objects). They have used gravitational microlensing to gauge the density of MACHOs, and the density is not high enough to account for the universe's missing gravitating matter. It appears that the majority of dark matter really is WIMPs (Weakly Interacting Massive Particles). Well, hopefully. I'd hate for dark matter to actually be composed of GIMPs (Gravitationally Interacting Massive Particles), because if they only interact with normal matter through gravitation, how the hell are we ever going to directly detect them? Maybe we could produce them in particle accelerator experiments and note their creation as mass or energy that apparently goes missing??

If the interaction is limited to gravitation, we'll have an extremely hard time with the progress of our knowledge.

Big planet? yes. But small enough not to be a star. The "only" was referring to "We're calling it a planet because it's too small for a star.

"Big" is misleading. If you would dump more and more gas into Jupiter, it wouldn't get proportionally bigger. It would crush its center more and more efficiently. It mass would increase, but its diameter wouldn't follow up that much.