Encyclopedia
CFBDSIR J145829+101343 (Coordinates: 14h 58m 29.0s, +10° 13′ 43″, 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, 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 (≈100 °C) and used to be known as the coolest known brown dwarf until the discovery of WISE 1828+2650 in August 2011.
- brown dwarfs
- 29.0s
- cfbdsir
1. 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.[1][2]
1.1. 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.[3][4]
2. 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.[5]
3. 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.[6]
CFBDSIR 1458+10 distance estimates
| Source | Parallax, mas | Distance, pc | Distance, ly | Ref. |
|---|---|---|---|---|
| Delorme et al. (2010) | ~23 | ~75 | [1] | |
| 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 | [7] |
| Dupuy & Liu (2012) | 31.3 ± 2.5 | 31.9+2.8−2.4 | 104.2+9.0−7.7 | [6] |
Non-trigonometric distance estimates are marked in
italic
. The best estimate is marked in
bold
.
4. Space Motion
CFBDSIR 1458+10 has proper motion of about 420 milliarcseconds per year.[6]
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 | [1][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 | [7] |
| Dupuy & Liu (2012) | 419.6 ± 2.6 | 155.50 ± 0.28 | 174.0 ± 2.0 | −381.8 ± 2.7 | [6] |
The most accurate estimates are marked in
bold
.
5. 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]
5.1. 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 | [5] |
6. 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.[1][4][8] In 2012 Liu et al. assigned it a spectral class Y0.[5]
7. 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.[9]
References
- 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. Bibcode: 2010A&A...518A..39D. https://dx.doi.org/10.1051%2F0004-6361%2F201014277
- 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).
- European Southern Observatory. "A Very Cool Pair of Brown Dwarfs", 23 March 2011 http://www.eso.org/public/news/eso1110/
- T10) Brown Dwarf in a Binary System". The Astrophysical Journal 740 (2): 108. doi:10.1088/0004-637X/740/2/108. Bibcode: 2011ApJ...740..108L. https://dx.doi.org/10.1088%2F0004-637X%2F740%2F2%2F108" id="ref_4">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. Bibcode: 2011ApJ...740..108L. https://dx.doi.org/10.1088%2F0004-637X%2F740%2F2%2F108
- 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. Bibcode: 2012ApJ...758...57L. https://dx.doi.org/10.1088%2F0004-637X%2F758%2F1%2F57
- 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. Bibcode: 2012ApJS..201...19D. https://dx.doi.org/10.1088%2F0067-0049%2F201%2F2%2F19
- 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) //arxiv.org/archive/astro-ph.SR
- Paul Gilster "Brown Dwarfs and Planets: A Blurry Boundary", Tau Zero Foundation, 23 March 2011 http://www.centauri-dreams.org/?p=17264
- Space.com "Coldest Known Star Is a Real Misfit", 23 March 2011 http://www.space.com
