Physical properties and astrometry of radio-emitting brown dwarf TVLM513-46546 revisited

Abstract

We present multi-epoch astrometric observations of the M9 ultra-cool dwarf TVLM513-46546 that is placed at the brown dwarf boundary. The new observations have been performed with the European VLBI Network (EVN) at 6cm band. The target has been detected at 7~epochs spanning three years, with measured quiescent emission flux in the range 180-300 muJy. We identified four short-duration flaring events (0.5-2 mJy) with very high circular polarization (~75%-100%). Properties of the observed radio flares support the physical model of the source that is characterized by the electron cyclotron maser instability responsible for outbursts of radio emission. Combined with Very Long Baseline Array (VLBA) earlier data, our detections make it possible to refine the absolute parallax pi=93.27(+0.18,-0.17) mas. Our measurements rule out TVLM513-46546 companions more massive than Jupiter in orbits with periods longer than ~1 yr.

arXiv comment10 pages, 9 figures, accepted to Monthly Notices of the RAS (MNRAS)

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Cited by in corpus (10)

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• Comparison of Gaia DR2 Parallaxes of Stars with VLBI Astrometry
• CCD Parallaxes for 309 Late-type Dwarfs and Subdwarfs
• An astrometric planetary companion candidate to the M9 Dwarf TVLM 513-46546
• On the Correlation between L Dwarf Optical and Infrared Variability and Radio Aurorae
• Probing the magnetosphere of the M8.5 dwarf TVLM513-46546 by modelling its auroral radio emission. Hint of star exoplanet interaction?
• The Occurrence Rate of Quiescent Radio Emission for Ultracool Dwarfs using a Generalized Semi-Analytical Bayesian Framework
• Sub-stellar companions of the young weak-line TTauri Star DoAr21
• Another look at AM Herculis $-$ radio-astrometric campaign with the e-EVN at 6 cm
• A search for millimeter emission from the coldest and closest brown dwarf with ALMA