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Post Info TOPIC: CFBDSIR J1458+1013B


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CFBDSIR 1458+1013
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Title: A WISE Observation of a coolest brown dwarf, CFBDSIR 1458+1013
Authors: Edward L. Wright (UCLA), Amy Mainzer, Chris Gelino, Davy Kirkpatrick

The Wide-field Infrared Survey Explorer (WISE) has detected the close binary brown dwarf system CFBDSIR 1458+1013AB as WISEP J145829.35+101341.8 with a combined magnitude at 4.6 microns of W2 = 15.4880.147. This allows a comparison with another "coolest" brown dwarf candidate WD 0806-661B that has been observed at 4.5 microns with [4.5] = 16.750.05. Here we use the WISE data to show that 1458+1013B is almost certainly warmer and more luminous than WD 0806-661B.

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CFBDSIR 1458+10 is a binary system of two brown dwarfs orbiting each other, located 75 light-years away from Earth discovered by the Canada-France Brown Dwarf Survey using the Canada-France-Hawaii Telescope, and first found to be a binary by the Keck II Observatory.
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RE: CFBDSIR J1458+1013B
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New Candidate For Coldest 'Star'

There is a new candidate for coldest known star: a brown dwarf with about the same temperature as a hot cup of coffee. That's cool enough to begin crossing the blurry line between small cold stars and big hot planets.
Brown dwarfs are essentially failed stars: they lack the mass and gravity to trigger the nuclear reactions that make stars shine brightly. The newly discovered brown dwarf, identified as CFBDSIR 1458+10B, is the smaller and dimmer member of a binary brown dwarf system located just 75 light-years from Earth. The pair was discovered by astronomers using the W. M. Keck Observatory and the Canada-France-Hawai'i Telescope (CFHT), both on the summit of Mauna Kea in Hawai'i, following up on earlier work done at European Southern Observatory's Very Large Telescope in Chile.

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Posts: 131433
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CFBDSIR 1458+10B
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A Very Cool Pair of Brown Dwarfs

Observations with the European Southern Observatorys Very Large Telescope, along with two other telescopes, have shown that there is a new candidate for the coldest known star: a brown dwarf in a double system with about the same temperature as a freshly made cup of tea hot in human terms, but extraordinarily cold for the surface of a star. This object is cool enough to begin crossing the blurred line dividing small cold stars from big hot planets.
Brown dwarfs are essentially failed stars: they lack enough mass for gravity to trigger the nuclear reactions that make stars shine. The newly discovered brown dwarf, identified as CFBDSIR 1458+10B, is the dimmer member of a binary brown dwarf system located just 75 light-years from Earth

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RE: CFBDSIR J1458+1013B
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Title: CFBDSIR J1458+1013B: A Very Cold (>T10) Brown Dwarf in a Binary System
Authors: Michael C. Liu, Philippe Delorme, Trent J. Dupuy, Brendan P. Bowler, Loic Albert, Etienne Artigau, Celine Reyle, Thierry Forveille, Xavier Delfosse
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Title: CFBDSIR J1458+1013B: A Very Cold (>T10) Brown Dwarf in a Binary System
Authors: Michael C. Liu, Philippe Delorme, Trent J. Dupuy, Brendan P. Bowler, Loic Albert, Etienne Artigau, Celine Reyle, Thierry Forveille, Xavier Delfosse

We have identified CFBDSIR J1458+10 as a 0.11" binary using Keck laser guide star AO imaging. We measure a parallactic distance of 23.12.4 pc to the system based on CFHT near-IR astrometry. We assign a spectral type of T9.5 to the integrated-light near-IR spectrum, and model atmospheres suggest a slightly higher temperature and surface gravity than the T10 dwarf UGPS J0722-05. Thus, CFBDSIR J1458+10AB is the coolest brown dwarf binary to date. Its secondary component has an absolute H-band magnitude that is 1.90.3 mag fainter than UGPS J0722-05, giving an inferred spectral type of >T10. The secondary's bolometric luminosity of ~2 x 10^{-7} L_sun makes it the least luminous known brown dwarf by a factor of 4-5. By comparing to models and known T9-T10 objects, we estimate a temperature of 37040 K and a mass of 6-15 Mjup for CFBDSIR J1458+10B. At such extremes, atmospheric models predict the onset of novel photospheric processes, namely the appearance of water clouds and the removal of strong alkali lines. Our photometry shows that strong CH_4 absorption persists at H-band; the J-K color is bluer than the latest known T dwarfs but not as blue as predicted by current models; and the J-H color delineates a possible inflection in the blueward trend for the latest T dwarfs. Given its low luminosity, atypical colors and cold temperature, CFBDSIR J1458+10B is a promising candidate for the hypothesized Y spectral class. Regardless of its ultimate classification, CFBDSIR J1458+10AB provides a new benchmark for measuring the properties of brown dwarfs and gas-giant planets, testing substellar models, and constraining the low-mass limit for star formation.

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