CFBDSIR 1458+10


CFBDSIR J145829+101343 is a binary system of two brown dwarfs of spectral classes T9 + Y0 orbiting each other, located in constellation Boötes about 104 light-years away from Earth.
The smaller companion, CFBDSIR 1458+10B, has a surface temperature of approx 370 K and used to be known as the coolest known brown dwarf until the discovery of WISE 1828+2650 in August 2011.

Discovery

CFBDSIR 1458+10 A was discovered in 2010 by Delorme et al. from the Canada-France Brown Dwarf Survey using the facilities MegaCam and mounted on the 3.6 m Canada-France-Hawaii Telescope, located on Mauna Kea Observatory, Hawaii. Image in z` band was taken on 2004 July 15 with MegaCam, and image in J band was taken on 2007 April 1 with WIRCam. In 2009 they made follow-up photometry, using the SOFI near infrared camera at the ESO 3.5 m New Technology Telescope at the La Silla Observatory, Chile. In 2010 Delorme et al. published a paper in Astronomy and Astrophysics where they reported the identification of 55 T-dwarfs candidates, six of which were photometrically confirmed as T-dwarfs, including 3 ultracool brown dwarfs, including CFBDSIR 1458+10.

Discovery of B

CFBDSIR 1458+10 B was discovered in 2011 by Liu et al. with laser guide star adaptive optics system of the 10 m Keck II Telescope on Mauna Kea, Hawaii, using infra-red camera NIRC2. In 2011 Liu et al. published a paper in The Astrophysical Journal where they presented discovery of CFBDSIR 1458+10 system component B. Also they presented a near-infrared trigonometric parallax of the system, measured using WIRCam on the Canada-France-Hawaii Telescope, Mauna Kea, in seven epochs during the 2009–2010; and spectroscopy with the X-Shooter spectrograph at the European Southern Observatory's Very Large Telescope Unit Telescope 2 in Chile, that allowed to calculate the temperature of the two brown dwarfs.

2012 Keck LGS-AO imaging

In 2012 CFBDSIR 1458+10 system was observed by Liu et al. with laser guide star adaptive optics system of the 10 m Keck II Telescope on Mauna Kea, Hawaii, using infra-red camera NIRC2. In 2012 Liu et al. published a paper in The Astrophysical Journal where they presented results of observations with Keck II LGS-AO of three brown dwarf binary systems, binarity of the two of which was first presented in this paper, and binarity of the other one, CFBDSIR 1458+10, was known before.

Distance

of CFBDSIR 1458+10, measured under The Hawaii Infrared Parallax Program by Dupuy & Liu in 2012, is 31.3 ± 2.5 mas, corresponding to a distance 31.9 pc, or 104.2 ly.
CFBDSIR 1458+10 distance estimates
SourceParallax, masDistance, pcDistance, lyRef.
Delorme et al. ~23~75
Liu et al. 43.3 ± 4.523.1 ± 2.475.3 ± 7.8
Dupuy & Liu
34.0 ± 2.629.495.9
Dupuy & Liu 31.3 ± 2.531.9104.2

Space motion

CFBDSIR 1458+10 has proper motion of about 420 milliarcseconds per year.
CFBDSIR 1458+10 proper motion estimates
Sourceμ,
mas/yr		P. A.,
°		μRA,
mas/yr		μDEC,
mas/yr		Ref.
Delorme et al. 444 ± 16157.5 ± 2.1170 ± 16−410 ± 16
Liu et al. 432 ± 6154.2 ± 0.7188−389
Dupuy & Liu
418.1 ± 3.2155.4 ± 0.4174.3 ± 3.0−380.0 ± 3.2
Dupuy & Liu 419.6 ± 2.6155.50 ± 0.28174.0 ± 2.0−381.8 ± 2.7

Physical properties

Using three models, Liu et al. calculated physical properties of CFBDSIR 1458+10 components.
From Lyon/COND models and Lbol:
Component and
assumed age		Mass,
MJup		Teff,
K		log g,
cm/s2		P,
yr
A 12.1 ± 1.9556 ± 484.45 ± 0.07
B 5.8 ± 1.3360 ± 404.10 ± 0.1035
A 31 ± 4605 ± 555.00 ± 0.08
B 14 ± 3380 ± 504.58 ± 0.1122

From Burrows et al. :
Component and
assumed age		Mass,
MJup		Teff,
K		log g,
cm/s2		P,
yr
A 13 ± 2550 ± 504.47 ± 0.07
B 6.8 ± 1.5350 ± 404.14 ± 0.1033
A 36 ± 4600 ± 605.06 ± 0.07
B 17 ± 4380 ± 504.65 ± 0.1220

From Burrows et al. models and M:
Component and
assumed age		Mass,
MJup		Teff,
K		log g,
cm/s2		P,
yr
A 11.1 ± 0.7479 ± 204.37 ± 0.03
B 7.6 ± 0.6386 ± 154.19 ± 0.0434
A >25>483>4.85
B 18.8 ± 1.3407 ± 154.69 ± 0.03<22

The adopted surface temperature of B is 370 ± 40 K, and adopted mass is 6-15 MJup.

Luminosity

At the time of its discovery, CFBDSIR 1458+10 B was the least luminous brown dwarf known.
CFBDSIR 1458+10 bolometric luminosity estimates
SourceLbol/L⊙ Lbol/L⊙ Ref.
Liu et al. 10−6.02 ± 0.14
10−6.74 ± 0.19
Liu et al. 10−5.72 ± 0.1310−6.53 ± 0.13

B's spectral class

In Liu et al. CFBDSIR 1458+10 B was assigned to the spectral class >T10, it was proposed that CFBDSIR 1458+10 B may be a member of the Y spectral class of brown dwarfs. In 2012 Liu et al. assigned it a spectral class Y0.

Water clouds

Due to the low surface temperature for a brown dwarf, CFBDSIR 1458+10 B may be able to form water clouds in its upper atmosphere.