Timing Analysis of the Periodic Radio and Optical Brightness Variations of the Ultracool Dwarf, TVLM 513-46546

Abstract

We describe the arrival time measurements and timing modeling of the periodic radio flares and optical brightness variations of the M9 ultracool dwarf, TVLM 513-46546. We confirm the stability of the observed period and determine its best-fit value to be 7054.468(+/-)0.007 s over the last 7 years, based on both the new and archival radio observations and the archival optical data. The period, when measured separately for the radio flare and the optical periodicities, is the same to within (+/-)0.02 s. We show that the radio flares are out of phase with respect to the optical brightness maxima by 0.41(+/-)0.02 of the period. Our analysis also reveals that, on shorter timescales, the period varies with the amplitude of (+/-)1-2 s about its long-term average and that these variations are correlated between the radio and the optical wavelengths. These results provide further evidence that TVLM 513-46546 is equipped with a stable, approximately dipolar magnetic field which powers the activity of the star observed over a wide wavelength range, and that the active area has been maintaining its identity and positional stability over no less than 7 years. A stepwise decline of the apparent radio flaring period of TVLM 513-46546 deduced from timing observations with the Arecibo radio telescope in late 2012 and early 2013 suggests that this effect may be the manifestation of differential rotation of the star.

Accepted for publication in ApJ; 11 pages, 4 figures, 1 table

References in corpus (11)

• Large-scale magnetic topologies of late M dwarfs
• Simulations of dynamo action in fully convective stars
• Confirmation of the Electron Cyclotron Maser Instability as the Dominant Source of Radio Emission from Very Low Mass Stars and Brown Dwarfs
• Periodic Bursts of Coherent Radio Emission from an Ultracool Dwarf
• Rotational Modulation of the Radio Emission from the M9 Dwarf TVLM 513-46546: Broadband Coherent Emission at the Substellar Boundary?
• The Arecibo Detection of the Coolest Radio-flaring Brown Dwarf
• Simultaneous Multi-Wavelength Observations of Magnetic Activity in Ultracool Dwarfs. I. The Complex Behavior of the M8.5 Dwarf TVLM513-46546
• Discovery of Radio Emission from the Tight M8 Binary: LP 349-25
• Rotational Modulation of M/L Dwarfs due to Magnetic Spots
• Optical variability of the ultracool dwarf TVLM 513-46546: evidence for inhomogeneous dust clouds
• Bayesian Analysis of Solar Oscillations

Cited by in corpus (16)

• A Panchromatic View of Brown Dwarf Aurorae
• A scaling relationship for non-thermal radio emission from ordered magnetospheres: from the top of the Main Sequence to planets
• Wideband Dynamic Radio Spectra of Two Ultra-cool dwarfs
• 154 MHz detection of faint, polarized flares from UV Ceti
• The Second Arecibo Search for 5 GHz Radio Flares from Ultracool Dwarfs
• The Discovery of Solar-like Activity Cycles Beyond the End of the Main Sequence?
• Rotation periods and photometric variability of rapidly rotating ultra-cool dwarfs
• In search of radio emission from exoplanets: GMRT observations of the binary system HD~41004
• Radio-flaring Ultracool Dwarf Population Synthesis
• Modelling the environment around five ultracool dwarfs via the radio domain
• Physical properties and astrometry of radio-emitting brown dwarf TVLM513-46546 revisited
• The photometric periods of rapidly rotating field ultra-cool dwarfs
• The milliarcsecond-scale radio structure of AB Dor A
• ROME III. The Arecibo Search for Star-Planet Interactions at 5 GHz
• Multibeam SETI Observations toward Nearby M dwarfs with FAST
• Magnetic-field oscillation model of pulsar radio emission: prediction of an observable effect