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.

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

References in corpus (7)

• The First Direct Measurements of Magnetic Fields on Very Low-Mass Stars
• Confirmation of the Electron Cyclotron Maser Instability as the Dominant Source of Radio Emission from Very Low Mass Stars and Brown Dwarfs
• Radio Observations of a Large Sample of Late-M, L, and T Dwarfs: The Distribution of Magentic Field Strengths
• Rotational Modulation of the Radio Emission from the M9 Dwarf TVLM 513-46546: Broadband Coherent Emission at the Substellar Boundary?
• A Jupiter-like Planet Orbiting the Nearby M Dwarf GJ832
• Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. I. The Complex Behavior of the M8.5 Dwarf TVLM513-46546
• Timing Analysis of the Periodic Radio and Optical Brightness Variations of the Ultracool Dwarf, TVLM 513-46546

Cited by in corpus (6)

• 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
• The Occurrence Rate of Quiescent Radio Emission for Ultracool Dwarfs using a Generalized Semi-Analytical Bayesian Framework
• A search for millimeter emission from the coldest and closest brown dwarf with ALMA