Kinematic analysis and membership status of TWA22 AB

Teixeira, R.; Ducourant, C.; Chauvin, G.; Krone-Martins, A.; Bonnefoy, M.; Song, Inseok

doi:10.1051/0004-6361/200912173

Cited by 36 publications

(48 citation statements)

References 36 publications

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“…But if we assume a separation of ∼0.1 AU to be compatible with the absence of PSF-lengthening, now the radial velocity wobble jumps to ±14 km s −1 over a 0.1 yr period. Such a variation was not detected in the radial velocity dataset (see Teixeira et al 2009). Finally, no photocenter scatter is present around our two-body orbital solution.…”

Section: Higher Multiplicity Hypothesismentioning

confidence: 89%

“…Once the distance d is known (17.5 pc, Teixeira et al 2009), the fit of the observational data allows determinating the 7 parameters T , a, e, i, Ω, ω, and t p . Then Kepler's third law leads to the total mass M.…”

Section: Astrometry Orbit and Dynamical Massmentioning

confidence: 99%

“…On January 8, 2006, the binary was actually very close to periastron. (Teixeira et al 2009), the absolute magnitudes were also derived. Since TWA22 is a young mid-M system, we monitored its photometric variations in the H band.…”

Section: Astrometry Orbit and Dynamical Massmentioning

confidence: 99%

“…Finally, Song et al (2006) discuss the Mamajek (2005) results that appeared to disagree with the very strong lithium line of the source. The proximity (17.5 ± 0.2 pc, see Teixeira et al 2009) and the reported youth of TWA22 by S03 made it consequently a potential target for detecting companions at small orbital radii.…”

Section: Introductionmentioning

confidence: 99%

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The young, tight, and low-mass binary TWA22AB: a new calibrator for evolutionary models?

Bonnefoy¹,

Chauvin²,

Dumas³

et al. 2009

A&A

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Context. Tight binaries discovered in young, nearby associations are ideal targets for providing dynamical mass measurements to test the physics of evolutionary models at young ages and very low masses. Aims. We report the binarity of TWA22 for the first time. We aim at monitoring the orbit of this young and tight system to determine its total dynamical mass using an accurate distance determination. We also intend to characterize the physical properties (luminosity, effective temperature, and surface gravity) of each component based on near-infrared photometric and spectroscopic observations. Methods. We used the adaptive-optics assisted imager NACO to resolve the components, to monitor the complete orbit and to obtain the relative near-infrared photometry of TWA22 AB. The adaptive-optics assisted integral field spectrometer SINFONI was also used to obtain medium-resolution (R λ = 1500−2000) spectra in JHK bands. Comparison with empirical and synthetic librairies were necessary for deriving the spectral type, the effective temperature, and the surface gravity for each component of the system. Results. Based on an accurate trigonometric distance (17.5±0.2 pc) determination, we infer a total dynamical mass of 220±21 M Jup for the system. From the complete set of spectra, we find an effective temperature T eff = 2900 +200 −200 K for TWA22 A and T eff = 2900 +200 −100 K for TWA22 B and surface gravities between 4.0 and 5.5 dex. From our photometry and an M6 ± 1 spectral type for both components, we find luminosities of log(L/L ) = −2.11 ± 0.13 dex and log(L/L ) = −2.30 ± 0.16 dex for TWA22 A and B, respectively. By comparing these parameters with evolutionary models, we question the age and the multiplicity of this system. We also discuss a possible underestimation of the mass predicted by evolutionary models for young stars close to the substellar boundary.

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Section: Higher Multiplicity Hypothesismentioning

confidence: 89%

Section: Astrometry Orbit and Dynamical Massmentioning

confidence: 99%

Section: Astrometry Orbit and Dynamical Massmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The young, tight, and low-mass binary TWA22AB: a new calibrator for evolutionary models?

Bonnefoy¹,

Chauvin²,

Dumas³

et al. 2009

A&A

Self Cite

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“…Membership and age of TWA stars have been much debated (Song et al 2003;Ortega et al 2004;Mamajek 2005;de la Reza et al 2006;Teixeira et al 2009;Schneider et al 2012b;Weinberger et al 2013). The conclusions of these authors relied heavily on the type and accuracy of the data they used.…”

Section: Introductionmentioning

confidence: 99%

The TW Hydrae association: trigonometric parallaxes and kinematic analysis

Ducourant

Teixeira

Galli

et al. 2014

A&A

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101

135

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Context. The nearby TW Hydrae association (TWA) is currently a benchmark for the study of the formation and evolution of young low-mass stars, circumstellar disks, and the imaging detection of planetary companions. For these studies, it is crucial to evaluate the distance to group members in order to access their physical properties. Membership of several stars is strongly debated and age estimates vary from one author to another with doubts about coevality. Aims. We revisit the kinematic properties of the TWA in light of new trigonometric parallaxes and proper motions to derive the dynamical age of the association and physical parameters of kinematic members. Methods. Using observations performed with the New Technology Telescope (NTT) from ESO we measured trigonometric parallaxes and proper motions for 13 stars in TWA. Results. With the convergent point method we identify a co-moving group with 31 TWA stars. We deduce kinematic distances for seven members of the moving group that lack trigonometric parallaxes. A traceback strategy is applied to the stellar space motions of a selection of 16 of the co-moving objects with accurate and reliable data yielding a dynamical age for the association of t 7.5 ± 0.7 Myr. Using our new parallaxes and photometry available in the literature we derive stellar ages and masses from theoretical evolutionary models. Conclusions. With new parallax and proper motion measurements from this work and current astrometric catalogs we provide an improved and accurate database for TWA stars to be used in kinematical analysis. We conclude that the dynamical age obtained via traceback strategy is consistent with previous age estimates for the TWA, and is also compatible with the average ages derived in the present paper from evolutionary models for pre-main-sequence stars.

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Membership status of TWA22AB

Teixeira¹,

Ducourant

Chauvin³

et al. 2009

Proc. IAU

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Abstract. Using the ESO NTT/SUSI2 telescope, we observed TWA22AB during five different observing runs over 1.2 years to measure its trigonometric parallax and proper motion. HARPS at the ESO 3.6m telescope was also used to measure the system's radial velocity over 2 years. Based on trigonometric-parallax, proper-motion and radial-velocity measurements, we re-analyzed the membership of TWA22AB of the young, nearby associations TW Hydrae, β Pictoris and Tucana-Horologium.

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Kinematic analysis and membership status of TWA22 AB

Cited by 36 publications

References 36 publications

The young, tight, and low-mass binary TWA22AB: a new calibrator for evolutionary models?

The young, tight, and low-mass binary TWA22AB: a new calibrator for evolutionary models?

The TW Hydrae association: trigonometric parallaxes and kinematic analysis

Membership status of TWA22AB

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