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

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

Post by Borislav on 5th April 2010, 3:20 am

http://arxiv.org/pdf/1004.0317
Here we report the discovery in the UKIDSS Galactic Plane Survey of a brown dwarf, UGPSJ0722-05, that is not only far less luminous and significantly cooler than previously known objects but also the nearest to the Solar System. The measured distance is 2.90.4 pc, from which we deduce an effective temperature in the range 400-500 K. The Gemini/NIRI near infrared spectrum displays deeper water vapour and methane absorption bands than the coolest known T dwarfs, and an unidentified absorption feature at 1.275 μm. Time will tell whether this object is regarded as a T10 dwarf or the first example of a new spectral type.

The SM2008 evolutionary models indicate that the mass is between 5 and 30 MJup

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

Post by Sirius_Alpha on 5th April 2010, 4:07 am

Goodness that's close. I wonder how many of these WISE will detect.

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

Post by Borislav on 5th April 2010, 4:21 am

The current distance estimate of 2.9 pc places it amongst the ten closest systems to the sun. The existence of this object in such a small fraction of the sky (~6%) suggests that even closer brown dwarfs will be found in future, either by UKIDSS or by new wide field facilities such as the NASA WISE satellite and the VISTA telescope.



Ie the probability of finding such objects closer Proxima Centauri is very real.

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

Post by Lazarus on 5th April 2010, 5:00 am

I wonder what the story is here. Looks like it has been submitted to Nature, but hasn't appeared yet in the journal, and the note suggests more data is being taken to refine the properties of the object (perhaps the reviewer suggested this?).

Then again, it's been posted to the arXiv now, so I guess it's fair game.
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Re: Discovery of a very cool brown dwarf amongst the ten nearest stars to the Solar System

Post by Borislav on 5th April 2010, 5:19 am

The object has a brightness J=16.5
http://www.ukidss.org/surveys/gps/gps.html
http://www.ukidss.org/surveys/surveys.html
limit GPS and LAS J=20

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

Post by Borislav on 5th April 2010, 7:28 am

Parallax 341 40 mas or 301-382 mas
http://www.recons.org/TOP100.posted.htm
It is between 5 and 10 to close to the solar system.

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

Post by Lazarus on 23rd June 2010, 3:12 pm

Paper at arXiv has been updated, reason given "The parallax measurement has changed significantly since version 1 so the paper has been withdrawn from Nature and submitted to MNRAS Letters"

The discovery of a very cool, very nearby brown dwarf in the Galactic plane

Old distance estimate = 2.9 0.4 pc
New distance estimate = 4.1+0.6-0.5 pc

Further away than initially thought...
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