6533b820fe1ef96bd1279a3f
RESEARCH PRODUCT
Astrometric detection of a low-mass companion orbiting the star AB Doradus
J. C. GuiradoJ. C. GuiradoR. H. FerrisS. SöderhjelmCarlos MartínM. FroeschleK. J. JohnstonK. A. KinghamPaul A. JonesFrédéric ArenouRobert A. PrestonDavid L. JaunceyJean-francois LestradeE. A. KingGraeme L. WhiteJohn ReynoldsP. M. MccullochJ. KovalevskyDayton L. JonesJ. O. MartinJames E. J. LovellAnastasios TzioumisLennart Lindegrensubject
010504 meteorology & atmospheric sciencesGalactic astronomyStellar massBrown dwarfAstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencesstars: low-mass0103 physical sciencesVery-long-baseline interferometryAstrophysics::Solar and Stellar Astrophysics010303 astronomy & astrophysicsAstrophysics::Galaxy Astrophysics0105 earth and related environmental sciencesPhysicsstars: individual (AB Doradus)[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]Astrophysics::Instrumentation and Methods for AstrophysicsAstronomyAstronomy and AstrophysicsAstrometryInterferometrySpace and Planetary Sciencetechniques: interferometricOrbital motionastrometryAstrophysics::Earth and Planetary Astrophysics[SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA]stars: kinematicsLow Massbrown dwarfsdescription
International audience; We report submilliarcsecond-precise astrometric measurements for the late-type star AB Doradus via a combination of VLBI (very long baseline interferometry) and HIPPARCOS data. Our astrometric analysis results in the precise determination of the kinematics of this star, which reveals an orbital motion readily explained as caused by gravitational interaction with a low-mass companion. From the portion of the reÑex orbit covered by our data and using a revised mass of the primary star (0.76 M _) derived from our new value of the parallax (66.3 mas \ n \ 67.2 mas), we Ðnd the dynamical mass of the newly discovered companion to be between 0.08 and 0.11 If accurate photometric information can M _. be obtained for the low-mass companion, our precise mass estimate could serve as an accurate calibration point for di †erent theoretical evolutionary models of low-mass objects. This represents the Ðrst detection of a low-mass stellar companion using VLBI, a technique that will become an important tool in future searches for planets and brown dwarfs orbiting other stars.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1997-12-01 |