Abstract
We report the discovery of a young, 016 binary, 2M2234+4041AB, found as the result of a Keck laser guide star adaptive optics imaging survey of young field ultracool dwarfs. Spatially resolved near-infrared photometry and spectroscopy indicate that the luminosity and temperature ratios of the system are near unity. From optical and near-infrared spectroscopy, we determine a composite spectral type of M6 for the system. Gravity-sensitive spectral features in the spectra of 2M2234+4041AB are best matched to those of young objects (1 Myr old). A comparison of the T eff and age of 2M2234+4041AB to evolutionary models indicates that the mass of each component is 0.10+0.075 -0.04 M ⊙. Emission lines of Hα in the composite optical spectrum of the system and Brγ in spatially resolved near-IR spectra of the two components indicate that the system is actively accreting. Both components of the system have IR excesses, indicating that they both harbor circumstellar disks. Though 2M2234+4041AB was originally identified as a young field dwarf, it lies 15 from the well-studied Herbig Ae/Be star, LkHα233. The distance to LkHα233 is typically assumed to be 880 pc. It is unlikely that 2M2234+4041AB could be this distant, as it would then be more luminous than any known Taurus objects of similar spectral type. We re-evaluate the distance to the LkHα233 group and find a value of 325 +72 -50 pc, based on the Hipparcos distance to a nearby B3-type group member (HD 213976). 2M2234+4041AB is the first low-mass star to be potentially associated with the LkHα233 group. At a distance of 325 pc, its projected physical separation is 51 AU, making it one of the growing number of wide, low-mass binaries found in young star-forming regions.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 824-835 |
| Number of pages | 12 |
| Journal | Astrophysical Journal |
| Volume | 697 |
| Issue number | 1 |
| DOIs | |
| State | Published - 2009 |
| Externally published | Yes |
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Keywords
- Binaries: visual
- Infrared: stars
- Stars: formation
- Stars: low-mass, brown dwarfs
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
- Nuclear and High Energy Physics
Cite this
2MASS 22344161+4041387AB : A wide, young, accreting, low-mass binary in the LkHα233 group. / Allers, K. N.; Liu, Michael C.; Shkolnik, Evgenya; Cushing, Michael C.; Dupuy, Trent J.; Mathews, Geoffrey S.; Reid, I. Neill; Cruz, Kelle L.; Vacca, W. D.
In: Astrophysical Journal, Vol. 697, No. 1, 2009, p. 824-835.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - 2MASS 22344161+4041387AB
T2 - A wide, young, accreting, low-mass binary in the LkHα233 group
AU - Allers, K. N.
AU - Liu, Michael C.
AU - Shkolnik, Evgenya
AU - Cushing, Michael C.
AU - Dupuy, Trent J.
AU - Mathews, Geoffrey S.
AU - Reid, I. Neill
AU - Cruz, Kelle L.
AU - Vacca, W. D.
PY - 2009
Y1 - 2009
N2 - We report the discovery of a young, 016 binary, 2M2234+4041AB, found as the result of a Keck laser guide star adaptive optics imaging survey of young field ultracool dwarfs. Spatially resolved near-infrared photometry and spectroscopy indicate that the luminosity and temperature ratios of the system are near unity. From optical and near-infrared spectroscopy, we determine a composite spectral type of M6 for the system. Gravity-sensitive spectral features in the spectra of 2M2234+4041AB are best matched to those of young objects (1 Myr old). A comparison of the T eff and age of 2M2234+4041AB to evolutionary models indicates that the mass of each component is 0.10+0.075 -0.04 M ⊙. Emission lines of Hα in the composite optical spectrum of the system and Brγ in spatially resolved near-IR spectra of the two components indicate that the system is actively accreting. Both components of the system have IR excesses, indicating that they both harbor circumstellar disks. Though 2M2234+4041AB was originally identified as a young field dwarf, it lies 15 from the well-studied Herbig Ae/Be star, LkHα233. The distance to LkHα233 is typically assumed to be 880 pc. It is unlikely that 2M2234+4041AB could be this distant, as it would then be more luminous than any known Taurus objects of similar spectral type. We re-evaluate the distance to the LkHα233 group and find a value of 325 +72 -50 pc, based on the Hipparcos distance to a nearby B3-type group member (HD 213976). 2M2234+4041AB is the first low-mass star to be potentially associated with the LkHα233 group. At a distance of 325 pc, its projected physical separation is 51 AU, making it one of the growing number of wide, low-mass binaries found in young star-forming regions.
AB - We report the discovery of a young, 016 binary, 2M2234+4041AB, found as the result of a Keck laser guide star adaptive optics imaging survey of young field ultracool dwarfs. Spatially resolved near-infrared photometry and spectroscopy indicate that the luminosity and temperature ratios of the system are near unity. From optical and near-infrared spectroscopy, we determine a composite spectral type of M6 for the system. Gravity-sensitive spectral features in the spectra of 2M2234+4041AB are best matched to those of young objects (1 Myr old). A comparison of the T eff and age of 2M2234+4041AB to evolutionary models indicates that the mass of each component is 0.10+0.075 -0.04 M ⊙. Emission lines of Hα in the composite optical spectrum of the system and Brγ in spatially resolved near-IR spectra of the two components indicate that the system is actively accreting. Both components of the system have IR excesses, indicating that they both harbor circumstellar disks. Though 2M2234+4041AB was originally identified as a young field dwarf, it lies 15 from the well-studied Herbig Ae/Be star, LkHα233. The distance to LkHα233 is typically assumed to be 880 pc. It is unlikely that 2M2234+4041AB could be this distant, as it would then be more luminous than any known Taurus objects of similar spectral type. We re-evaluate the distance to the LkHα233 group and find a value of 325 +72 -50 pc, based on the Hipparcos distance to a nearby B3-type group member (HD 213976). 2M2234+4041AB is the first low-mass star to be potentially associated with the LkHα233 group. At a distance of 325 pc, its projected physical separation is 51 AU, making it one of the growing number of wide, low-mass binaries found in young star-forming regions.
KW - Binaries: visual
KW - Infrared: stars
KW - Stars: formation
KW - Stars: low-mass, brown dwarfs
UR - http://www.scopus.com/inward/record.url?scp=66649108830&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=66649108830&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/697/1/824
DO - 10.1088/0004-637X/697/1/824
M3 - Article
VL - 697
SP - 824
EP - 835
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
ER -