CFBDSIR J145829+101343
Binary star system
From Wikipedia, the free encyclopedia
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,[2] located in constellation Boötes about 104 light-years away from Earth.[4]
 CFBDSIR 1458+10 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes[1] |
| Right ascension | 14h 58m 29.0s |
| Declination | +10° 13′ 43″ |
| Characteristics | |
| Whole system (MKO filter system) | |
| Apparent magnitude (Y) | 20.58 ± 0.21[2] |
| Apparent magnitude (J) | 19.67 ± 0.02[3][2] |
| Apparent magnitude (H) | 20.06 ± 0.10[3][2] |
| Apparent magnitude (K) | 20.50 ± 0.24[2] |
| Component A (MKO filter system) | |
| Spectral type | T9[2] |
| Apparent magnitude (Y) | 20.81 ± 0.21[2] |
| Apparent magnitude (J) | 19.83 ± 0.02[2] |
| Apparent magnitude (H) | 20.18 ± 0.10[2] |
| Apparent magnitude (K) | 20.63 ± 0.24[2] |
| Component B (MKO filter system) | |
| Spectral type | Y0V[2] |
| Apparent magnitude (Y) | 22.36 ± 0.24[2] |
| Apparent magnitude (J) | 21.85 ± 0.06[2] |
| Apparent magnitude (H) | 22.51 ± 0.16[2] |
| Apparent magnitude (K) | 22.83 ± 0.30[2] |
| Astrometry | |
| Proper motion (μ) | RA: 174.0 ± 2.0[4] mas/yr Dec.: −381.8 ± 2.7[4] mas/yr |
| Parallax (π) | 31.3±2.5 mas[4] |
| Distance | 104 ± 8 ly (32 ± 3 pc) |
| Orbit[5] | |
| Primary | A |
| Name | B |
| Period (P) | 20+17 −6—35+28 −10 yr |
| Details | |
| Component A | |
| Mass | (11.1 ± 0.7)—(36 ± 4)[5] MJup |
| Radius | 0.15 R☉ |
| Luminosity (bolometric) | 10−5.72 ± 0.13[2] L☉ |
| Surface gravity (log g) | (4.37 ± 0.03)—(5.06 ± 0.07)[5] cgs |
| Temperature | (479 ± 20)—(605 ± 55)[5] K |
| Component B | |
| Mass | 6–15[5] MJup |
| Radius | 0.13 R☉ |
| Luminosity (bolometric) | 10−6.53 ± 0.13[2] L☉ |
| Surface gravity (log g) | (4.10 ± 0.10)—(4.69 ± 0.03)[5] cgs |
| Temperature | 370 ± 40[5] K |
| Position (relative to A) | |
| Component | B |
| Epoch of observation | UT 2012 April 13 |
| Angular distance | 127.2 ± 1.4 mas [2] |
| Position angle | 318.1 ± 1.1° [2] |
| Projected separation | 4.06 AU[2][4] |
| Other designations | |
| CFBDSIR J1458+1013 CFBDS 1458 CFBDS J145829+101343 WISEPA J145829.35+101341.8[3] WISE J145829.40+101341.7[6] | |
| Database references | |
| SIMBAD | data |
The smaller companion, CFBDSIR 1458+10B, has a surface temperature of approx 370 K (≈100 °C)[7][8]. It used to be known as the coolest known brown dwarf until the discovery of WISE 1828+2650 in August 2011.[9]
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.[10][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.[7][5]
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.[2]
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.[4]
CFBDSIR 1458+10 distance estimates
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.[4]
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 | [10][5] |
| Liu et al. (2011) | 432 ± 6 | 154.2 ± 0.7 | 188 | −389 | [5] |
| Dupuy & Liu (2012) (preprint version 1) | 418.1 ± 3.2 | 155.4 ± 0.4 | 174.3 ± 3.0 | −380.0 ± 3.2 | [11] |
| Dupuy & Liu (2012) | 419.6 ± 2.6 | 155.50 ± 0.28 | 174.0 ± 2.0 | −381.8 ± 2.7 | [4] |
The most accurate estimates are marked in bold.
Physical properties
Using three models, Liu et al. calculated physical properties of CFBDSIR 1458+10 components.[5]
From Lyon/COND models and Lbol:
From Burrows et al. (1997) models and Lbol):
From Burrows et al. (2003) models and M(J):
The adopted surface temperature of B is 370 ± 40 K, and adopted mass is 6-15 MJup.[5]
Luminosity
At the time of its discovery, CFBDSIR 1458+10 B was the least luminous brown dwarf known.[5]
CFBDSIR 1458+10 bolometric luminosity estimates
B's spectral class
In Liu et al. (2011) CFBDSIR 1458+10 B was assigned to the spectral class >T10,[5] it was proposed that CFBDSIR 1458+10 B may be a member of the Y spectral class of brown dwarfs.[10][5][12] In 2012 Liu et al. assigned it a spectral class Y0.[2]
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.[8]
See also
- WISE J0336−0143 – first Y + Y binary brown dwarf system discovered
The other two brown dwarf binary systems, observed by Liu et al. with Keck II LGS-AO in 2012:[2]
- WISE 1217+1626 (T9 + Y0, binarity was newly discovered)
- WISE 1711+3500 (T8 + T9.5, binarity was newly discovered)
Notes
- 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).