A planet without a star may have been found

[Maxinquaye]

http://www.astronomynow.com/news/n1211/15rogue/

A possible free-floating exoplanet, drifting through interstellar space without a star of its own to orbit, has been discovered a hundred light years from Earth. If confirmed, it will be the first of its kind to be proven to exist - and there may be billions more like it out there.

This is so cool!

Still, I can't help but put this in. Just to throw it out there.

http://www.youtube.com/watch?v=-bzWSJG93P8

What if it's not a planet... per se?

[Gil Paul]

Great link! Made me smile!

In regards to the planet - just one more illustration of how little we really know. I would like to believe that humanity has finally figured out that just about anything is possible! Of course, too many people can only manage to believe in that which can be seen with their own eyes.

[RichardGarfinkle]

The thing that may make this not unusual is that it may be a brown dwarf. Brown dwarfs form exactly the way stars do, but they lack enough mass to get fusion started.

Here's a pretty good illustrated description of stellar formation.
http://abyss.uoregon.edu/~js/ast122/lectures/lec13.html

The point is that there could be quite a large number of brown dwarfs out there. They would look like free floating planets but are really stars that never started shining.

More analysis would need to be done to tell which this is.

[Maxinquaye]

Isn't that a mere classification thing though? I mean, every celestial body is born in roughly the same way - the difference between a star and a planet is, in essence, which one passed beyond a mass barrier to ignite fusion and which didn't.

Someone said once that Sol is a binary system, except Jupiter never got the last bit of mass in order to ignite. That is of course the premise behind 2010, where Jupiter is ignited artificially.

[Don]

Originally Posted by Maxinquaye

What if it's not a planet... per se?

It could be the Debt Star.

[RichardGarfinkle]

Originally Posted by Maxinquaye

Isn't that a mere classification thing though? I mean, every celestial body is born in roughly the same way - the difference between a star and a planet is, in essence, which one passed beyond a mass barrier to ignite fusion and which didn't.

Someone said once that Sol is a binary system, except Jupiter never got the last bit of mass in order to ignite. That is of course the premise behind 2010, where Jupiter is ignited artificially.

Yes and no or kind of. It is true that the distinction between a gas giant, a brown dwarf, and a star is largely one of mass. But there's also what's swirling around what as formation happens.

One way to think about the development of the entire non-dark-matter, non-dark-energy universe (i.e. the small part we baryonic bigots think is important) is that small asymmetries in the initial distribution of hydrogen (also helium, lithium and other odds and ends) led gravitationally to clumping together into proto-galactic clusters which further clumped into proto-galaxies, proto-stars etc. If enough of this concentrates down to enough stuff in a small enough volume fusion starts. Smaller sized lumps can become brown dwarfs or gas giants.

But there's also heavier gunk out there, the dust that forms planetesimals out of which planets like ours (the small rocky ones) are formed).
http://en.wikipedia.org/wiki/Planetesimal

In a system such as ours there was enough gunk and planetesimals for even our gas giants to get a belly full of heavier stuff probably lodged inside them (it's hard to say). There's certainly a lot of junk rotating around them in the form of moons and rings.

So there's a question about whether this 'rogue planet' had an opportunity as part of a forming solar system to attract that kind of junk or not.

The origin of this object (free standing brown dwarf or orphaned planet) would probably determine a lot about what's inside it and possibly what's in orbit around it.

[clintl]

Originally Posted by RichardGarfinkle

The thing that may make this not unusual is that it may be a brown dwarf. Brown dwarfs form exactly the way stars do, but they lack enough mass to get fusion started.

Here's a pretty good illustrated description of stellar formation.
http://abyss.uoregon.edu/~js/ast122/lectures/lec13.html

The point is that there could be quite a large number of brown dwarfs out there. They would look like free floating planets but are really stars that never started shining.

More analysis would need to be done to tell which this is.

True, but there are likely planets out there that have been ejected from their solar systems as well.

[Vince524]

I find it very annoying that the death star joke was done before I got here.

However, isn't more likely that it's a Dyson Sphere? http://jharbour.com/Dyson_sphere_exterior.jpg

[clintl]

Originally Posted by Vince524

I find it very annoying that the death star joke was done before I got here.

However, isn't more likely that it's a Dyson Sphere? http://jharbour.com/Dyson_sphere_exterior.jpg

Next up - a star with a solid metallic ring around it, right in the middle of the habitable zone.

[Kaiser-Kun]

If it starts speaking in Orson Welles' voice, run and call the Autobots.

[blacbird]

Astronomers have been speculating about the possibilities of "rogue planets" for quite some time. Problem is, such objects are bloody difficult to detect, even if they might be quite near us in celestial-scale terms. But there's no theoretical reason to think they don't exist, and every theoretical reason to believe that multitudes of them do.

caw

[Williebee]

Does it, by chance, look like a big blue phone box?

[MattW]

Sorry to burst everyone's science-boners, but this doesn't really exist because exoplanets aren't covered in Genesis.

[kuwisdelu]

Dibs.

[StormChord]

Damn it, I wanted to dibsie it! Thanks a lot, space pirate asuka.

Anyway, that really does sound awesome. I'm curious, though - wouldn't a free-floating planet eventually be drawn into orbit around a star anyway? I mean, space is big, but gravity doesn't have an outer limit for any given object, so probabilistically speaking wouldn't it be drawn into or in orbit around a sufficiently large gravitic attractor?

[blacbird]

Originally Posted by StormChord

I'm curious, though - wouldn't a free-floating planet eventually be drawn into orbit around a star anyway? I mean, space is big, but gravity doesn't have an outer limit for any given object, so probabilistically speaking wouldn't it be drawn into or in orbit around a sufficiently large gravitic attractor?

No. This object is already in orbit around the center of our galaxy, which is the gravitational core. But the gravitational attraction of other stars, given the distances involved between them, is so tenuous that "capture" by one would be exceedingly unlikely. In fact, stars born close together in star-forming nebulae generally drift apart in their adolescence into the kind of loneliness the sun currently inhabits. The only stars gravitationally bound to one another are those siblings which formed as part of the same orbital system.

caw

[benbradley]

Here's some new (to this article and to me, anyway) news, an actual image of a planet that orbits another star:
http://www.slate.com/blogs/bad_astro...arby_star.html

[StormChord]

Originally Posted by blacbird

No. This object is already in orbit around the center of our galaxy, which is the gravitational core. But the gravitational attraction of other stars, given the distances involved between them, is so tenuous that "capture" by one would be exceedingly unlikely. In fact, stars born close together in star-forming nebulae generally drift apart in their adolescence into the kind of loneliness the sun currently inhabits. The only stars gravitationally bound to one another are those siblings which formed as part of the same orbital system.

caw

Oh, okay. Thanks!