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]
 CFBDSIR 1458+10 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| 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 | Y0V[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 mas[3] |
| Distance | 104 ± 8 ly (32 ± 3 pc) |
| Orbit[4] | |
| Primary | A |
| Companion | B |
| Period (P) | 20+17 −6—35+28 −10 yr |
| Details | |
| Component A | |
| Mass | (11.1 ± 0.7)—(36 ± 4)[4] MJup |
| Radius | 0.15 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 | |
| Mass | 6–15[4] MJup |
| Radius | 0.13 R☉ |
| Luminosity (bolometric) | 10−6.53 ± 0.13[1] L☉ |
| Surface gravity (log g) | (4.10 ± 0.10)—(4.69 ± 0.03)[4] cgs |
| Temperature | 370 ± 40[4] K |
| Position (relative to A) | |
| Component | B |
| Epoch of observation | UT 2012 April 13 |
| Angular distance | 127.2 ± 1.4 mas [1] |
| Position angle | 318.1 ± 1.1° [1] |
| Projected separation | 4.06 AU [1][3] |
| Other designations | |
| Database references | |
| SIMBAD | data |
The smaller companion, CFBDSIR 1458+10B, has a surface temperature of approx 370 K (≈100 °C)[6][7]. It used to be known as the coolest known brown dwarf until the discovery of WISE 1828+2650 in August 2011.[8]
Discovery
editCFBDSIR 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
editCFBDSIR 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
editIn 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
editTrigonometric 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
editCFBDSIR 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
editUsing 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
editAt 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
editIn 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
editDue 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
edit- 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:[1]
- WISE 1217+1626 (T9 + Y0, binarity was newly discovered)
- WISE 1711+3500 (T8 + T9.5, binarity was newly discovered)
Notes
edit- ^ 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
edit- ^ a b c d e f g h i j k l m n o p q r s t u v w x Liu, Michael C.; Dupuy, Trent J.; Bowler, Brendan P.; Leggett, Sandy 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. arXiv:1206.4044. Bibcode:2012ApJ...758...57L. doi:10.1088/0004-637X/758/1/57. S2CID 118402490.
- ^ a b c Kirkpatrick, J. Davy; Cushing, Michael C.; Gelino, Christopher R.; Griffith, Roger L.; Skrutskie, Michael F.; Marsh, Kenneth A.; Wright, Edward L.; Mainzer, Amy K.; Eisenhardt, Peter R.; McLean, Ian S.; Thompson, Maggie A.; Bauer, James M.; Benford, Dominic J.; Bridge, Carrie R.; Lake, Sean E.; Petty, Sara M.; Stanford, Spencer Adam; Tsai, Chao-Wei; Bailey, Vanessa; Beichman, Charles A.; Bloom, Joshua S.; Bochanski, John J.; Burgasser, Adam J.; Capak, Peter L.; Cruz, Kelle L.; Hinz, Philip M.; Kartaltepe, Jeyhan S.; Knox, Russell P.; Manohar, Swarnima; Masters, Daniel; Morales-Calderon, Maria; Prato, Lisa A.; Rodigas, Timothy J.; Salvato, Mara; Schurr, Steven D.; Scoville, Nicholas Z.; Simcoe, Robert A.; Stapelfeldt, Karl R.; Stern, Daniel; Stock, Nathan D.; Vacca, William D. (2011). "The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)". The Astrophysical Journal Supplement. 197 (2): 19. arXiv:1108.4677v1. Bibcode:2011ApJS..197...19K. doi:10.1088/0067-0049/197/2/19. S2CID 16850733.
- ^ a b c d e f g h i 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. arXiv:1201.2465. Bibcode:2012ApJS..201...19D. doi:10.1088/0067-0049/201/2/19. S2CID 119256363.
- ^ a b c d e f g h i j k l m n o p q Liu, Michael C.; Delorme, Philippe; Dupuy, Trent J.; Bowler, Brendan P.; Albert, Loïc; Artigau, Étienne; Reylé, Céline; Forveille, Thierry; Delfosse, Xavier (2011). "CFBDSIR J1458+1013B: A Very Cold (>T10) Brown Dwarf in a Binary System". The Astrophysical Journal. 740 (2): 108. arXiv:1103.0014. Bibcode:2011ApJ...740..108L. doi:10.1088/0004-637X/740/2/108. S2CID 118344589.
- ^ Kirkpatrick, J. Davy; Gelino, Christopher R.; Cushing, Michael C.; Mace, Gregory N.; Griffith, Roger L.; Skrutskie, Michael F.; Marsh, Kenneth A.; Wright, Edward L.; Eisenhardt, Peter R.; McLean, Ian S.; Mainzer, Amy K.; Burgasser, Adam J.; Tinney, Chris G.; Parker, Stephen; Salter, Graeme (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. arXiv:1205.2122. Bibcode:2012ApJ...753..156K. doi:10.1088/0004-637X/753/2/156. S2CID 119279752.
- ^ a b Liu, Michael; Delorme, Philippe; Veillet, Christian; Hook, Richard; "eso1110 — Science Release: A Very Cool Pair of Brown Dwarfs", European Southern Observatory, 23 March 2011
- ^ a b Space.com staff, "Coldest Known Star is a Real Misfit", Space.com, 23 March 2011
- ^ Choi, Charles Q.; "How Cold Is a Y Dwarf Star? Even You Are Warmer", Space.com, 25 August 2011
- ^ a b c d Delorme, Philippe; Albert, Loïc; Forveille, Thierry; Artigau, Étienne; Delfosse, Xavier; Reylé, Céline; Willott, Chris J.; Bertin, Emmanuel; Wilkins, Stephen M.; Allard, France; Arzoumanian, Doris (2010). "Extending the Canada-France brown dwarfs survey to the near-infrared: first ultracool brown dwarfs from CFBDSIR". Astronomy and Astrophysics. 518: A39. arXiv:1004.3876. Bibcode:2010A&A...518A..39D. doi:10.1051/0004-6361/201014277. S2CID 119086889.
- ^ a b Dupuy, Trent J.; Liu, Michael C. (2012). "The Hawaii Infrared Parallax Program. I. Ultracool Binaries and the L/T Transition". The Astrophysical Journal Supplement Series. 201 (2): 19. arXiv:1201.2465v1. Bibcode:2012ApJS..201...19D. doi:10.1088/0067-0049/201/2/19. S2CID 119256363.
- ^ Gilster, Paul; "Brown Dwarfs and Planets: A Blurry Boundary", Tau Zero Foundation, 23 March 2011