Pulsating young brown dwarfs

Abstract

We present the results of a nonadiabatic, linear stability analysis of models of very low-mass stars (VLMSs) and brown dwarfs (BDs) during the deuterium burning phase in the center. We find unstable fundamental modes with periods varying between ~5 hr for a 0.1 Msun star and ~1 hr for a 0.02 Msun BD. The growth time of the instability decreases with decreasing mass and remains well below the deuterium burning time scale in the mass range considered (0.1--0.02 Msun). These results are robust against variations of the relevant input physics in the evolutionary models. We identify possible candidates for pulsational variability among known VLMSs and BDs in nearby star forming regions whose location in the HR diagram falls within or close to the boundary of the instability strip. Finally, we discuss the possibility that the variability observed in a few objects with periods of ~1 hr can be interpreted in terms of pulsation.

5 pages, 3 figures, A&A Letters (in press)

References in corpus (4)

• New Low-Mass Members of the Taurus Star-Forming Region
• Rotation and accretion of very low mass objects in the SigmaOri cluster
• Rotational periods of very young brown dwarfs and very low-mass stars in ChaI
• Photometric variability of a young, low-mass brown dwarf

Cited by in corpus (25)

• The Formation and Early Evolution of Low-mass Stars and Brown Dwarfs
• Precision photometric monitoring of very low mass Sigma Orionis cluster members: variability and rotation at a few Myr
• A wide deep infrared look at the Pleiades with UKIDSS: new constraints on the substellar binary fraction and the low mass IMF
• Variability of the Lowest Mass Objects in the AB Doradus Moving Group
• Young stars and brown dwarfs surrounding Alnilam (eps Ori) and Mintaka (del Ori)
• 3D simulations of M star atmosphere velocities and their influence on molecular FeH lines
• Asteroseismology of the Nearby SN-II Progenitor Rigel Part II. ε-Mechanism Triggering Gravity-Mode Pulsations?
• Radial and rotational velocities of young brown dwarfs and very low-mass stars in the Upper Scorpius OB association and the rho Ophiuchi cloud core
• Stellar oscillations. II The non-adiabatic case
• Pulsations in M dwarf stars
• Pulsational instabilities driven by the $\epsilon$ mechanism in hot pre-horizontal branch stars I. The Hot-Flasher Scenario
• A Pulsation Search Among Young Brown Dwarfs and Very Low Mass Stars
• Asteroseismology across the HR diagram
• Near-Infrared Light Curves of the Brown Dwarf Eclipsing Binary 2MASS J05352184-0546085: Can Spots Explain the Temperature Reversal?
• Stellar Pulsations in Beyond Horndeski Gravity Theories
• Rotation periods and photometric variability of rapidly rotating ultra-cool dwarfs
• Complex Modulation of Rapidly Rotating Young M Dwarfs: Adding Pieces to the Puzzle
• Young brown dwarfs at high cadence: Warm Spitzer time series monitoring of very low mass Sigma Orionis cluster members
• Doppler-beaming in the Kepler light curve of LHS 6343 A
• Astrophysics in 2005
• Variability in the Lambda Orionis cluster substellar domain
• Fast Photometric Variability of Very Low Mass Stars in IC 348: Detection of Superflare in an M-dwarf
• Variability in SSTc2d J163134.1-240100, a brown dwarf with quasi-spherical mass loss
• Dynamic Photometric Variability in Three Young Brown Dwarfs in Taurus: Detection of Optical Flares with TESS data
• The Cohesive Object Sequence: The Mass-Density Distribution of Astronomical Objects from Asteroids to Stars