TR: Lone Jupiter Discovered Wandering Nine Light-Years Away

[bystander]

Lone 'Jupiter' Discovered Wandering Nine Light-Years Away
Technology Review: physics arXiv blog: 2010 Apr 06

One of the sun's closest neighbours is a wandering, Jupiter-sized object just nine light-years away, say astronomers.
...
Lucas and company say this body has a radius about the same as Jupiter's and a similar temperature of about 500K. That makes it the coolest brown dwarf ever discovered. Spectroscopic studies of its atmosphere show signs of methane and even water vapor.

This combination of temperature and evidence of water will make UGPSJ0722-05 a fascinating talking point for astrobiologists. Jupiter's beautiful coloured bands are the result of organic molecules in its atmosphere. So the question of what could be floating around UGPSJ0722-05's atmosphere will be hotly debated.

Part of this debate will focus on another interesting observation about this body: its atmosphere also contains something that is absorbing radiation at a wavelength of 1.25 micrometres. As yet, nobody is able to explain this mysterious absorption feature but it may mean that UGPSJ0722-05 is an entirely new type of brown dwarf.

Best of all is that fact that this Jupiter-like object is only nine light-years away, making it one of the sun's 10 nearest neighbors and a candidate for significantly more investigation in the near future.

Expect to hear more about UGPSJ0722-05 from Lucas and others. A decent name would be a good start.

Discovery of a very cool brown dwarf amongst the ten nearest stars to the Solar System

• arXiv.org > astro-ph > arXiv:1004.0317 > 2010 Apr 02

[bystander]

A Hidden Cosmic Neighbor: Cool Brown Dwarf Found Lurking Near Our Solar System
Discover Blogs - 80beats - 2010 Apr 12

Astronomers have discovered the closest new star to us that’s been spotted in 63 years. Though “star” might be a stretch, depending upon whom you ask.

The new find, UGPS 0722-05, is less than 10 light years from here. But sky-watchers missed it for so long because it’s a brown dwarf, a member of the murky class of celestial objects that linger between gas giant planets and low-mass stars. Brown dwarfs have so little mass that they never get hot enough to sustain the nuclear fusion reactions that power stars like the sun. Still, they do shine, because they glow from the heat of their formation, then cool and fade [New Scientist]. This dwarf’s temperature is somewhere between 266 and 446 degrees Fahrenheit, making it the coldest scientists have even seen. With its minimal activity, the brown dwarf gives off just 0.000026 percent the amount of light that our sun does.

Like dwarf planets, which cast aside the 9-planet solar system of our childhoods and riled Pluto-philes everywhere, brown dwarfs don’t lend themselves to simple scientific definitions. The International Astronomical Union sets the planet–brown dwarf boundary at 13 times the mass of Jupiter. But that mass limit is an imperfect definition—what of brown dwarf–size bodies that orbit stars, behaving themselves like supersized planets [Scientific American]? The nomenclature could get even messier when the details of this new find are confirmed. Study leader Philip Lucas and his colleagues suggest that the newly discovered brown dwarf is so cool that it might be the first member of a new class of ultralow temperature dwarfs. Although one fingerprint of such a new class, absorption of infrared light by ammonia, appears to be missing, only “time will tell” if the discovery merits a new classification, the researchers note [Science News].

Lucas’ team’s paper is currently being submitted to the journal Nature, where the peer-review process should help to verify how close the team was with its parallax measurement of the brown dwarf’s distance. If they’re correct, UGPS 0722-05 will not only beat out the previous record-holders for proximity to Earth—a binary set of brown dwarfs in the Epsilon Indi system, about 11.8 light-years away—it would also suggest that perhaps more of these shadowy celestial objects linger even closer to us.

Brown dwarfs, also known as failed stars, are intermediate in mass between stars and planets.
Researchers have now found the closest brown dwarf to Earth, just nine light-years distant.
It's also the coolest brown dwarf yet seen. (NASA)