WISEPC J121756.91+162640.2AB - Double brown dwarf or Brown dwarf-planet system?

View previous topic View next topic Go down

WISEPC J121756.91+162640.2AB - Double brown dwarf or Brown dwarf-planet system?

Post by Edasich on 12th November 2013, 4:47 am

Following EPE's upper limit, the Y-dwarf WISEPC J121756.91+162640.2 B should be placed in the planetary regime with 22 Jupiter masses. Shouldn't it?
 
Resolved Spectroscopy of the T8.5 and Y0-0.5 Binary WISEPC J121756.91+162640.2AB
 
We present 0.9 - 2.5 um resolved spectra for the ultracool binary WISEPC J121756.91+162640.2AB. The system consists of a pair of brown dwarfs that straddles the currently defined T/Y spectral type boundary. We use synthetic spectra generated by model atmospheres that include chloride and sulfide clouds (Morley et al.), the distance to the system (Dupuy & Kraus), and the radius of each component based on evolutionary models (Saumon & Marley) to determine a probable range of physical properties for the binary. The effective temperature of the T8.5 primary is 550 - 600 K, and that of the Y0 - Y0.5 secondary is 450 K. The atmospheres of both components are either free of clouds or have extremely thin cloud layers. We find that the masses of the primary and secondary are 30 and 22 M_Jup, respectively, and that the age of the system is 4 - 8 Gyr. This age is consistent with astrometric measurements (Dupuy & Kraus) that show that the system has kinematics intermediate between those of the thin and thick disks of the Galaxy. An older age is also consistent with an indication by the H - K colors that the system is slightly metal-poor.
avatar
Edasich
dM star
dM star

Number of posts : 1502
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: WISEPC J121756.91+162640.2AB - Double brown dwarf or Brown dwarf-planet system?

Post by Sirius_Alpha on 12th November 2013, 5:19 am

I'm perfectly content to call this one a binary brown dwarf. I think it's clear that the formation mechanism was not consistent with that of "normal" planets. I guess it's all up to the EPE's criterion and how rigidly it wants to stick to that.

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3416
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: WISEPC J121756.91+162640.2AB - Double brown dwarf or Brown dwarf-planet system?

Post by Edasich on 12th November 2013, 7:01 am

In any case...
 
http://exoplanet.eu/catalog/wise_1217+16a_b/ (though the "Ab" sounds weird)
 
So also the WISE "double brown dwarfs" in Liu et al. (2012) should be included in the list since secondaries have masses even below 10 Jupiter masses.
avatar
Edasich
dM star
dM star

Number of posts : 1502
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: WISEPC J121756.91+162640.2AB - Double brown dwarf or Brown dwarf-planet system?

Post by Sirius_Alpha on 12th November 2013, 7:36 am

Really EPE? Really? Rolling Eyes 

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3416
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: WISEPC J121756.91+162640.2AB - Double brown dwarf or Brown dwarf-planet system?

Post by Lazarus on 12th November 2013, 2:48 pm

Edasich wrote:In any case...
 
http://exoplanet.eu/catalog/wise_1217+16a_b/ (though the "Ab" sounds weird)
Not as bad as WD 0806-661B, which they designated WD 0806-661Bb which is certainly incorrect... http://exoplanet.eu/catalog/wd_0806-661b_b/
avatar
Lazarus
dG star
dG star

Number of posts : 2783
Registration date : 2008-06-12

View user profile

Back to top Go down

Re: WISEPC J121756.91+162640.2AB - Double brown dwarf or Brown dwarf-planet system?

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum