GOING ROGUE: This artist's impression shows the free-floating planet CFBDSIR2149, at 100 light-years away the closest such "rogue" world to our own solar system. It does not orbit a star and hence does not shine by reflected light; the faint glow it emits can only be detected in infrared light.
Image: ESO/L. Calçada/P. Delorme/Nick Risinger (skysurvey.org)/R. Saito/VVV Consortium
Astronomers have discovered a potential "rogue" alien planet wandering alone just 100 light-years from Earth, suggesting that such starless worlds may be extremely common across the galaxy.
The free-floating object, called CFBDSIR2149, is likely a gas giant planet four to seven times more massive than Jupiter, scientists say in a new study unveiled today (Nov. 14). The planet cruises unbound through space relatively close to Earth (in astronomical terms), perhaps after being booted from its own solar system.
"If this little object is a planet that has been ejected from its native system, it conjures up the striking image of orphaned worlds, drifting in the emptiness of space," study leader Philippe Delorme, of the Institute of Planetology and Astrophysics of Grenoble in France, said in a statement.
Orphan planet, or something else?
Delorme and his team discovered CFBDSIR2149 using the Canada-France-Hawaii Telescope, then examined its properties with the European Southern Observatory's Very Large Telescope in Chile. [Video: Rogue Planet Has No Parent Star]
The newfound object appears to be among a stream of young stars called the AB Doradus moving group, the closest such stream to our own solar system.
Scientists think the AB Doradus stars all formed together between 50 million and 120 million years ago. If CFBDSIR2149 is indeed associated with the group — and researchers cite a nearly 90 percent probability — then the object is similarly young.
And if the discovery team is right about CFBDSIR2149's age, the body is likely a planet, with an average temperature of 806 degrees Fahrenheit (430 degrees Celsius), researchers said.
There's still a slight chance that CFBDSIR2149 is a brown dwarf — a strange object that's larger than a planet but too small to trigger the internal nuclear fusion reactions required to become a full-fledged star. Additional observations should help decide the matter.
"We need new observations to confirm that this object belongs to the AB Doradus moving group," Delorme told SPACE.com via email. "With a good distance measurement and a more accurate proper motion, we will be able to increase (or decrease) the probability that it is indeed a planet."
The new study was published today in the journal Astronomy & Astrophysics.
Billions of starless planets?
The discovery of a starless alien planet would not be shocking, at least not anymore. In the last year or so, astronomers have spotted a number of such orphan worlds — so many, in fact, that some scientists think parentless planets are the rule rather than the exception.
One 2011 study, for example, estimated that rogue worlds outnumber "normal" planets with obvious host stars by at least 50 percent throughout the Milky Way. If that's the case, the galaxy that includes Earth probably also hosts billions of orphan planets.
And gas giants may be in the minority among these solitary wanderers, researchers say.
"We now know that such massive planets are rare and that Neptunes or Earth-mass planets are much more common," Delorme said. "We also know that massive objects are more difficult to eject [from solar systems] than light ones. If you follow the rationale, you deduce that ejected exo-Neptunes and ejected exo-Earths should be much more common than objects like CFBDSIR2149."
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16 Comments
Add CommentAs an interested layperson, one of the things I've always wondered is if enough of such objects could account for the "missing mass" now attributed to dark matter and/or dark energy. I've never heard a anyone address the possibility, so I assume it so obviously not possible that it does not warrant consideration, but is this actually the case?
Reply | Report Abuse | Link to thisExoplanets are considered in dark matter estimates, yes. But even at the highest possible density, it wouldn't be enough to account for "dark matter".
Reply | Report Abuse | Link to this(I forgot to mention that they are included in "MACHOs" (*MAssive Compact Halo Objects) when estimated, along with other possible massive baryonic matter sources, such as black holes, neutron stars, brown dwarfs, and so on.
Reply | Report Abuse | Link to thisThanks, that was driving me nuts :)
Reply | Report Abuse | Link to thisIt's Nibiru!
Reply | Report Abuse | Link to thisI could not find how close CFBDSIR2149 is to the stars in the AB Doradus moving group. From wiki I see that 10 of the stars share a volume of about 10 parsecs in diameter. These 10 stars would have an approximate average distance of at least 4 parsecs from each other. So I would guess CFBDSIR2149 would be no closer than 4 parsecs to its closest star. I guess it seems reasonable that this is a rogue planet if several stars are at similar distances to CFBDSIR2149 and those distances are greater than 4 parsecs (so as to disrupt any potential orbiting).
Reply | Report Abuse | Link to thisAnyone know the mathematics of this? That is, how do we know the planet is rogue and not in a very large orbit? Or just as two or more stars could orbit each other? What are the largest theoretical orbits (given specific masses)?
Has the hypothetical red dwarf, Nemesis, been debunked? Nemesis was supposed to be orbiting the Sun at approximately 0.5 parsecs. [Note: I just brought up Nemesis as a comparison of orbits (0.5 vs 4 parsecs). I am not saying that it exists.]
OK, so if (as the article states) we don't yet have telescopes powerful enough to directly image planets this far away, then most (or as far as I know, all) planets outside the solar system are detected by their effects on light from their star, either eclipsing said star, or causing its path to 'wobble' slightly.
Reply | Report Abuse | Link to thisSo can someone explain to this poor layman (since the article didn't) just how THIS planet was detected?
From Universe Today: "The object turned up at infrared wavelengths in the Canada-France Brown Dwarfs Survey (CFBDS)"
Reply | Report Abuse | Link to this"I have seen the dark universe yawning
Reply | Report Abuse | Link to thisWhere the black planets roll without aim-
Where they roll in their horror unheeded,
Without knowledge or luster or name."
(H. P. Lovecraft - 1918)
@Bozobub...this is a warm one(read new one) so we can actually detect it thru radiation(infrared). What about the ones that formed at near the beginning or even a billion years ago. What if the universe is swarming with small non sun objects.
Reply | Report Abuse | Link to thisLets see...if we had an earth size object every tenth of a light year then we would end up with something like...1000000 * 1000000 * 300000 or 10 to the 17th objects in our galaxy, not including the halo which is probably 10 times more than that, so lets say 10 to the 18th. It take about a million earths to equal the sun(actually 1/3) so now were back to 10 to the 12th suns in "dark" mater.
Don't dismiss something just because we can't detect it yet....
I am always exiting about the new finding of Astrology. Wish someday space travel could become true.
Reply | Report Abuse | Link to thisThanks, Bird. U T has some pretty interesting stuff. I usually look there and spacedotcom each day before I check out SA.
Reply | Report Abuse | Link to thisI suspect there are even more of these ejected planets out there than the best estimates, maybe even a Neburu (NOT trying to get That started!).
Given how cluttered the galaxy is, I would bet that, over the billions of years, there have been thousands of such rogue planets, but that many or most of them either got nabbed by a passing star system or got tragically destroyed (either by black hole or by getting too-too close to their new star). Out here on the outskirts of the galaxy, though, it's easier for such planets to survive as rogues. I wouldn't be surprised if there are more planets like this out there to be found.
Reply | Report Abuse | Link to thisThe sun mass is about 1000 times bigger than Jupiter. If rogue planets are 50% more common than "regular" planets and if we consider our solar system as a small one with 8 planets representing less than 0,2% of solar mass, so, lets say, all rogue planets out there would represent something like 0,5% of all stars' mass. Double the estimation and the additional mass will be marginal. So, nope, rogue planets do not account for the dark matter mass.
Reply | Report Abuse | Link to thiswell, join the club.
Reply | Report Abuse | Link to thisThere *are* NINE planets. Pluto got mugged in a lecture hall.
Reply | Report Abuse | Link to this