A multiwavelength radial velocity search for planets around the brown dwarf LP 944-20

Abstract

The nearby brown dwarf LP 944-20 has been monitored for radial velocity variability at optical and near-infrared wavelengths using the VLT/UVES and the Keck/NIRSPEC spectrographs, respectively. The UVES radial velocity data obtained over 14 nights spanning a baseline of 841 days shows significant variability with an amplitude of 3.5 km s${}^{-1}$. The periodogram analysis of the UVES data indicates a possible period between 2.5 hours and 3.7 hours, which is likely due to the rotation of the brown dwarf. However, the NIRSPEC data obtained over 6 nights shows an rms dispersion of only 0.36 km s${}^{-1}$ and do not follow the periodic trend. These results indicate that the variability seen with UVES is likely to be due to rotationally modulated inhomogeneous surface features. We suggest that future planet searches around very low-mass stars and brown dwarfs using radial velocities will be better conducted in the near-infrared than in the optical.

accepted by ApJ Letters

References in corpus (21)

• Galactic Stellar and Substellar Initial Mass Function
• Rotation and Activity in Mid-M to L Dwarfs
• An empirical criterion to classify T Tauri stars and substellar analogs using low-resolution optical spectroscopy
• Magnetic field generation in fully convective rotating spheres
• Activity in Very Cool Stars: Magnetic Dissipation in late-M and L Dwarf Atmospheres
• The Onset of Planet Formation in Brown Dwarf Disks
• Large-scale alpha^2-dynamo in low-mass stars and brown dwarfs
• Spectroscopy of New Substellar Candidates in the Pleiades: Towards a Spectral Sequence for Young Brown Dwarfs
• The Substellar Mass Function in sigma Orionis
• L-dwarf variability: I-band observations
• Chandra Detection of an X-ray Flare from the Brown Dwarf LP 944-20
• First Detection of Millimeter Dust Emission from Brown Dwarf Disks
• Discovery of a Planetary-Mass Brown Dwarf with a Circumstellar Disk
• The Magnetic Properties of an L Dwarf Derived from Simultaneous Radio, X-ray, and H-alpha Observations
• Searching for Weather in Brown Dwarfs
• The Intermediate Age Brown Dwarf LP 944-20
• Photometric Variability in the Ultracool Dwarf BRI 0021-0214: Possible Evidence for Dust Clouds
• Limits on the infrared photometric monitoring of brown dwarfs
• Companions of old brown dwarfs, and very low mass stars
• The field brown dwarf LP 944-20 and the Castor moving group
• XMM-Newton observations of the nearby brown dwarf LP 944-20

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