Lost in space: rogue planet spotted?
November 16, 2012
Artist’s impression of the free-floating planet CFBDSIR J214947.2-040308.9 (credit: ESO)
Astronomers have identified an object that could be a planet wandering through space without a parent star at a distance of about 100 light-years. Its closeness and the absence of a nearby bright star have allowed the team to study its atmosphere in great detail.
Free-floating planets are planetary-mass objects that roam through space without any ties to a star. Possible examples of such objects have been found before, but without knowing their ages, it was not possible for astronomers to know whether they were really planets or brown dwarfs — “failed” stars that lack the bulk to trigger the reactions that make stars shine.
But astronomers have now discovered an object, labelled CFBDSIR2149, that seems to be part of a nearby stream of young stars known as the AB Doradus Moving Group. The researchers found the object in observations from the Canada-France-Hawaii Telescope and harnessed the power of ESO’s Very Large Telescope to examine its properties.
The AB Doradus Moving Group is the closest such group to the Solar System. Its stars drift through space together and are thought to have formed at the same time. If the object is associated with this moving group — and hence it is a young object — it is possible to deduce much more about it, including its temperature, mass, and what its atmosphere is made of. There remains a small probability that the association with the moving group is by chance.
The link between the new object and the moving group is the vital clue that allows astronomers to find the age of the newly discovered object. This is the first isolated planetary mass object ever identified in a moving group, and the association with this group makes it the most interesting free-floating planet candidate identified so far.
Free-floating objects like CFBDSIR2149 are thought to form either as normal planets that have been booted out of their home systems, or as lone objects like the smallest stars or brown dwarfs. In either case these objects are intriguing — either as planets without stars, or as the tiniest possible objects in a range spanning from the most massive stars to the smallest brown dwarfs.
References:
- P. Delorme et al.,CFBDSIR2149-0403: a 4–7 Jupiter-mass free-floating planet in the young moving group AB Doradus?, Astronomy & Astrophysics, 2012, DOI: 10.1051/0004-6361/201219984
- P. Delorme et al.,CFBDSIR2149-0403: a 4–7 Jupiter-mass free-floating planet in the young moving group AB Doradus?, open access preprint
Comments (5)
by Foye Lowe
I’m pretty sure that “artist’s impression” has way too much tilt. And the color is definitely off . . .
by Lord Penguin
Tilt is more or less meaningless without a host star to compare it to (although the galactic plane does work as a reference, it doesn’t make any difference to the planet which way it is tilted except in special conditions). The way it appears tilted to us is just based on what angle we see it at, and there isn’t really any way to tell until actual pictures are produced, or its origin is pinpointed. As for the color, it probably glows a faint red (possibly only infrared) from internal heat, rather than blue.
by Ian
It’s the Cybermen!
by Gorden Russell
There were rogue planets in “When Worlds Collide.” That became a fun movie back in the day. Just watch and see those scientific illiterates who believe that the Mayan calendar predicts doom on December 21st. They will say that this is the planet they have expected all along. None of them will pay attention to the part that says this planet is 100 light years away. They just don’t understand the great distances in the vastness of space.
by zen
100 light years is not a “vast distance.” Relatively, it’s in our neighborhood.