Astronomers using ESO's Very Large Telescope and the Canada-France-Hawaii Telescope have identified a body that is very probably a planet wandering through space without a parent star. This is the most exciting free-floating planet candidate so far and the closest such object to the Solar System at a distance of about 100 light-years. Its comparative proximity, and the absence of a bright star very close to it, has allowed the team to study its atmosphere in great detail. This object also gives astronomers a preview of the exoplanets that future instruments aim to image around stars other than the Sun.
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.
"Looking for planets around their stars is akin to studying a firefly sitting one centimetre away from a distant, powerful car headlight," says Philippe Delorme (Institut de planetologie et d'astrophysique de Grenoble, CNRS/Universite Joseph Fourier, France), lead author of the new study. "This nearby free-floating object offered the opportunity to study the firefly in detail without the dazzling lights of the car messing everything up."
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.
"These objects are important, as they can either help us understand more about how planets may be ejected from planetary systems, or how very light objects can arise from the star formation process," says Philippe Delorme. "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."
These worlds could be common -- perhaps as numerous as normal stars. If CFBDSIR2149 is not associated with the AB Doradus Moving Group it is trickier to be sure of its nature and properties, and it may instead be characterised as a small brown dwarf. Both scenarios represent important questions about how planets and stars form and behave.
"Further work should confirm CFBDSIR2149 as a free-floating planet," concludes Philippe Delorme. "This object could be used as a benchmark for understanding the physics of any similar exoplanets that are discovered by future special high-contrast imaging systems, including the SPHERE instrument that will be installed on the VLT."
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Its on-going mission, to explore the strange new comet, to seek out new plumes of dust and gas, spewing from the warming surface of 67P/Churyumov-Gerasimenko
Somewhere dark and icy on a comet 320 million miles away, the history-making, comet-bouncing Philae spacecraft is sleeping. Its batteries are depleted and there isn’t enough sunlight to recharge. But while the lander finished its primary job, collecting invaluable data on the surface of comet 67P/Churyumov-Gerasimenko, the Rosetta mission is far from over. For many scientists, the excitement is just beginning.
Black Beauty, a 4.4 billion-year-old martian meteorite, has captivated collectors and scientists
After landing a probe on an icy comet, the European Space Agency (ESA) is now heading to scorching-hot Mercury with its BepiColombo spacecraft.
To see back in time, you need a massive telescope—one big enough to capture light from when the first galaxies were formed, 13.5 billion years ago. Astronomers are clamoring to see this light, so NASA is obliging them by building the James Webb Space Telescope.
No one knows what the planet Gliese 667Cc looks like. We know that it is about 22 light-years from Earth, a journey of lifetimes upon lifetimes. But no one can say whether it is a world like ours, with oceans and life, cities and single-malt Scotch. Only a hint of a to-and-fro oscillation in the star it orbits, detectable by Earth's most sensitive telescopes and spectrographs, lets astronomers say the planet exists at all.
A top U.S. Air Force official on Wednesday said she is "pretty optimistic" that privately held Space Exploration Technologies will eventually be certified to launch U.S. military satellites into orbit but declined comment on the timing of such an action.
A dramatic study—and an equally dramatic video simulation—reveal a cataclysmic cosmic event
Dan Winters There’s no way to anticipate the emotional impact of leaving your home planet. You look down at Earth and realize: You’re not on it. It’s breathtaking. It’s surreal. It’s a “we’re not in Kansas anymore, Toto” kind of feeling.
A Russian spacecraft is visiting satellites, raising fears it could be part of an anti-satellite programme – if it's not an inspection craft