Astronomy:CFBDSIR 1458+10

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Coordinates: Sky map 14h 58m 29.0s, +10° 13′ 43″

CFBDSIR J145829+101343
Observation data
Equinox J2000.0]] (ICRS)
Constellation Boötes
Right ascension  14h 58m 29.0s
Declination 10° 13′ 43″
Characteristics
Whole system (MKO filter system)
Apparent magnitude (Y) 20.58 ± 0.21[1]
Apparent magnitude (J) 19.67 ± 0.02[2][1]
Apparent magnitude (H) 20.06 ± 0.10[2][1]
Apparent magnitude (K) 20.50 ± 0.24[1]
Component A (MKO filter system)
Spectral type T9[1]
Apparent magnitude (Y) 20.81 ± 0.21[1]
Apparent magnitude (J) 19.83 ± 0.02[1]
Apparent magnitude (H) 20.18 ± 0.10[1]
Apparent magnitude (K) 20.63 ± 0.24[1]
Component B (MKO filter system)
Spectral type Y0[1]
Apparent magnitude (Y) 22.36 ± 0.24[1]
Apparent magnitude (J) 21.85 ± 0.06[1]
Apparent magnitude (H) 22.51 ± 0.16[1]
Apparent magnitude (K) 22.83 ± 0.30[1]
Astrometry
Proper motion (μ) RA: 174.0 ± 2.0[3] mas/yr
Dec.: −381.8 ± 2.7[3] mas/yr
Parallax (π)31.3 ± 2.5[3] mas
Distance104 ± 8 ly
(32 ± 3 pc)
Orbit[4]
PrimaryA
CompanionB
Period (P)20+17−6—35+28−10 yr
Details
Component A
Mass(11.1 ± 0.7)—(36 ± 4)[4] MJup
Radius0.15 R
Luminosity (bolometric)10−5.72 ± 0.13[1] L
Surface gravity (log g)(4.37 ± 0.03)—(5.06 ± 0.07)[4] cgs
Temperature(479 ± 20)—(605 ± 55)[4] K
Component B
Mass6–15[4] MJup
Radius0.13 R
Luminosity (bolometric)10−6.53 ± 0.13[1] L
Surface gravity (log g)(4.10 ± 0.10)—(4.69 ± 0.03)[4] cgs
Temperature370 ± 40[4] K
Position (relative to A)
ComponentB
Epoch of observationUT 2012 April 13
Angular distance127.2 ± 1.4 mas [1]
Position angle318.1 ± 1.1° [1]
Observed separation
(projected)
4.06 AU [1][3]
Other designations
CFBDSIR J1458+1013
CFBDS 1458
CFBDS J145829+101343
WISEPA J145829.35+101341.8[2]
WISE J145829.40+101341.7[5]
Database references
SIMBADdata
Extrasolar Planets
Encyclopaedia
data

CFBDSIR J145829+101343 (designation abbreviated to CFBDSIR 1458+10, or CFBDSIR J1458+1013) is a binary system of two brown dwarfs of spectral classes T9 + Y0 orbiting each other,[1] located in constellation Boötes about 104 light-years away from Earth.[3]

The smaller companion, CFBDSIR 1458+10B, has a surface temperature of approx 370 K (≈100 °C)[6][7] and used to be known as the coolest known brown dwarf until the discovery of WISE 1828+2650 in August 2011.[8]

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 WIRCam 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 (NTT) 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 (later than T7 dwarfs and possible Y dwarfs), including CFBDSIR 1458+10.[9][note 1]

Discovery of B

CFBDSIR 1458+10 B was discovered in 2011 by Liu et al. with laser guide star (LGS) adaptive optics (AO) system of the 10 m Keck II Telescope on Mauna Kea, Hawaii, using infra-red camera NIRC2 (the observations were made on 2010 May 22 and 2010 July 8 (UT)). In 2011 Liu et al. published a paper in The Astrophysical Journal where they presented discovery of CFBDSIR 1458+10 system component B (the only discovery presented in the article). Also they presented a near-infrared (J-band) trigonometric parallax of the system, measured using WIRCam on the Canada-France-Hawaii Telescope (CFHT), 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 (VLT) Unit Telescope 2 (UT2) in Chile (the observations have been performed from May 5 to July 9, 2010), that allowed to calculate the temperature (and other physical parameters) of the two brown dwarfs.[6][4]

2012 Keck LGS-AO imaging

In 2012 CFBDSIR 1458+10 system was observed by Liu et al. with laser guide star (LGS) adaptive optics (AO) system of the 10 m Keck II Telescope on Mauna Kea, Hawaii, using infra-red camera NIRC2 (the observations were made on 2012 April 13 (UT)). 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.[1]

Distance

Trigonometric parallax 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+2.8−2.4 pc, or 104.2+9.0−7.7 ly.[3]

CFBDSIR 1458+10 distance estimates

Source Parallax, mas Distance, pc Distance, ly Ref.
Delorme et al. (2010) ~23 ~75 [9]
Liu et al. (2011) 43.3 ± 4.5 23.1 ± 2.4 75.3 ± 7.8 [4]
Dupuy & Liu (2012)
(preprint version 1)
34.0 ± 2.6 29.4+2.4−2.1 95.9+7.9−6.7 [10]
Dupuy & Liu (2012) 31.3 ± 2.5 31.9+2.8−2.4 104.2+9.0−7.7 [3]

Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.

Space motion

CFBDSIR 1458+10 has proper motion of about 420 milliarcseconds per year.[3]

CFBDSIR 1458+10 proper motion estimates

Source μ,
mas/yr
P. A.,
°
μRA,
mas/yr
μDEC,
mas/yr
Ref.
Delorme et al. (2010) 444 ± 16 157.5 ± 2.1 170 ± 16 −410 ± 16 [9][4]
Liu et al. (2011) 432 ± 6 154.2 ± 0.7 188 −389 [4]
Dupuy & Liu (2012)
(preprint version 1)
418.1 ± 3.2 155.4 ± 0.4 174.3 ± 3.0 −380.0 ± 3.2 [10]
Dupuy & Liu (2012) 419.6 ± 2.6 155.50 ± 0.28 174.0 ± 2.0 −381.8 ± 2.7 [3]

The most accurate estimates are marked in bold.

Physical properties

Using three models, Liu et al. calculated physical properties of CFBDSIR 1458+10 components.[4]

From Lyon/COND models and Lbol:

Component and
assumed age
Mass,
MJup
Teff,
K
log g,
cm/s2
P,
yr
A (for 1 Gyr) 12.1 ± 1.9 556 ± 48 4.45 ± 0.07
B (for 1 Gyr) 5.8 ± 1.3 360 ± 40 4.10 ± 0.10 35+28−10
A (for 5 Gyr) 31 ± 4 605 ± 55 5.00 ± 0.08
B (for 5 Gyr) 14 ± 3 380 ± 50 4.58 ± 0.11 22+18−6

From Burrows et al. (1997) models and Lbol):

Component and
assumed age
Mass,
MJup
Teff,
K
log g,
cm/s2
P,
yr
A (for 1 Gyr) 13 ± 2 550 ± 50 4.47 ± 0.07
B (for 1 Gyr) 6.8 ± 1.5 350 ± 40 4.14 ± 0.10 33+27−7
A (for 5 Gyr) 36 ± 4 600 ± 60 5.06 ± 0.07
B (for 5 Gyr) 17 ± 4 380 ± 50 4.65 ± 0.12 20+17−6

From Burrows et al. (2003) models and M(J):

Component and
assumed age
Mass,
MJup
Teff,
K
log g,
cm/s2
P,
yr
A (for 1 Gyr) 11.1 ± 0.7 479 ± 20 4.37 ± 0.03
B (for 1 Gyr) 7.6 ± 0.6 386 ± 15 4.19 ± 0.04 34+28−10
A (for 5 Gyr) >25 >483 >4.85
B (for 5 Gyr) 18.8 ± 1.3 407 ± 15 4.69 ± 0.03 <22

The adopted surface temperature of B is 370 ± 40 K, and adopted mass is 6-15 MJup.[4]

Luminosity

At the time of its discovery, CFBDSIR 1458+10 B was the least luminous brown dwarf known.[4]

CFBDSIR 1458+10 bolometric luminosity estimates

Source Lbol/L (A) Lbol/L (B) Ref.
Liu et al. (2011) 10−6.02 ± 0.14
((1.1 ± 0.4) × 10−6)
10−6.74 ± 0.19
((2.0 ± 0.9) × 10−7)
[4]
Liu et al. (2012) 10−5.72 ± 0.13 10−6.53 ± 0.13 [1]

B's spectral class

In Liu et al. (2011) CFBDSIR 1458+10 B was assigned to the spectral class >T10,[4] it was proposed that CFBDSIR 1458+10 B may be a member of the Y spectral class of brown dwarfs.[9][4][11] In 2012 Liu et al. assigned it a spectral class Y0.[1]

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.[7]

See also

The other two brown dwarf binary systems, observed by Liu et al. with Keck II LGS-AO in 2012:[1]

  • WISE 1217+1626 (T9 + Y0, binarity was newly discovered)
  • WISE 1711+3500 (T8 + T9.5, binarity was newly discovered)

Notes

  1. The other two ultracool brown dwarfs are CFBDSIR221903.07+002417.92 and CFBDSIR221505.06+003053.11. Three earlier type confirmed T dwarfs, as well as 49 unconfirmed candidates, are not listed in the article. (However, it is mentioned, that two of three earlier type confirmed T dwarfs are re-identifications of already spectroscopically confirmed CFBDS brown dwarfs).

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 Liu, Michael C.; Dupuy, Trent J.; Bowler, Brendan P.; Leggett, S. K.; Best, William M. J. (2012). "Two Extraordinary Substellar Binaries at the T/Y Transition and the Y-band Fluxes of the Coolest Brown Dwarfs". The Astrophysical Journal 758 (1): 57. doi:10.1088/0004-637X/758/1/57. Bibcode2012ApJ...758...57L. 
  2. 2.0 2.1 2.2 Kirkpatrick, J. Davy; Cushing, Michael C.; Gelino, Christopher R.; Griffith, Roger L.; Skrutskie, Michael F.; Marsh, Kenneth A.; Wright, Edward L.; Mainzer, A. et al. (2011). "The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)". The Astrophysical Journal Supplement 197 (2): 19. doi:10.1088/0067-0049/197/2/19. Bibcode2011ApJS..197...19K. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Dupuy, Trent J.; Liu, Michael C. (2012). "The Hawaii Infrared Parallax Program. I. Ultracool Binaries and the L/T Transition". The Astrophysical Journal Supplement 201 (2): 19. doi:10.1088/0067-0049/201/2/19. Bibcode2012ApJS..201...19D. 
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 4.15 4.16 Liu, Michael C.; Delorme, Philippe; Dupuy, Trent J.; Bowler, Brendan P.; Albert, Loic; Artigau, Etienne; Reylé, Celine; Forveille, Thierry et al. (2011). "CFBDSIR J1458+1013B: A Very Cold (>T10) Brown Dwarf in a Binary System". The Astrophysical Journal 740 (2): 108. doi:10.1088/0004-637X/740/2/108. Bibcode2011ApJ...740..108L. 
  5. Kirkpatrick, J. D.; Gelino, C. R.; Cushing, M. C.; Mace, G. N.; Griffith, R. L.; Skrutskie, M. F.; Marsh, K. A.; Wright, E. L. et al. (2012). "Further Defining Spectral Type "Y" and Exploring the Low-mass End of the Field Brown Dwarf Mass Function". The Astrophysical Journal 753 (2): 156. doi:10.1088/0004-637X/753/2/156. Bibcode2012ApJ...753..156K. 
  6. 6.0 6.1 European Southern Observatory. "A Very Cool Pair of Brown Dwarfs", 23 March 2011
  7. 7.0 7.1 Space.com "Coldest Known Star Is a Real Misfit", 23 March 2011
  8. Space.com "Y dwarf star? Because they're cool, that's Y!", 26 August 2011
  9. 9.0 9.1 9.2 9.3 Delorme, P.; Albert, L.; Forveille, T.; Artigau, E.; Delfosse, X.; Reylé, C.; Willott, C. J.; Bertin, E. et al. (2010). "Extending the Canada-France brown dwarfs survey to the near-infrared: first ultracool brown dwarfs from CFBDSIR". Astronomy and Astrophysics 518: A39. doi:10.1051/0004-6361/201014277. Bibcode2010A&A...518A..39D. 
  10. 10.0 10.1 Dupuy, Trent J.; Liu, Michael C. (2012). "The Hawaii Infrared Parallax Program. I. Ultracool Binaries and the L/T Transition". arXiv:1201.2465v1 [astro-ph.SR]. Cite has empty unknown parameter: |bibcode= (help)
  11. Paul Gilster "Brown Dwarfs and Planets: A Blurry Boundary", Tau Zero Foundation, 23 March 2011

External links