Browsing FAS Scholarly Articles by Keyword "radio continuum: stars"
Now showing items 1-12 of 12
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An Astrometric Search for a Sub-stellar Companion of the M8.5 Dwarf TVLM 513–46546 Using Very Long Baseline Interferometry
(IOP Publishing, 2013)We conducted multi-epoch VLBI observations to search for astrometric reflex motion caused by a sub-stellar companion of the M8.5 dwarf TVLM 513–46546. The observations yield an absolute parallax corresponding to a distance ... -
The First Millimeter Detection of a Non-Accreting Ultracool Dwarf
(IOP Publishing, 2015)The well-studied M9 dwarf TVLM 513–46546 is a rapid rotator (Prot ∼ 2 hr) hosting a stable, dipolar magnetic field of ∼3 kG surface strength. Here we report its detection with ALMA at 95 GHz at a mean flux density of 56 ± ... -
The First Vlbi Detection of an Ultracool Dwarf: Implications for the Detectability of Sub-Stellar Companions
(IOP Publishing, 2009)We present milliarcsecond-resolution radio very long baseline interferometry (VLBI) observations of the ultracool dwarfs TVLM 513–46546 (M8.5) and 2MASS J00361617+1821104 (L3.5) in an attempt to detect sub-stellar companions ... -
High-Precision Radio and Infrared Astrometry of Lspm J1314+1320ab. I. Parallax, Proper Motions, and Limits on Planets
(American Astronomical Society, 2016)We present multi-epoch astrometric radio observations with the Very Long Baseline Array (VLBA) of the young ultracool-dwarf binary LSPM J1314+1320AB . The radio emission comes from the secondary star. Combining the VLBA ... -
Periodic Radio and Hα emission from the L dwarf binary 2MASSW J0746425+200032: exploring the magnetic field topology and radius of an L dwarf
(IOP Publishing, 2009)We present an 8.5-hour simultaneous radio, X-ray, UV, and optical observation of the L dwarf binary 2MASSW J0746425+200032. We detect strong radio emission, dominated by short-duration periodic pulses at 4.86 GHz with P = ... -
Periodic Radio Emission From the M7 Dwarf 2mass J13142039+1320011: Implications for the Magnetic Field Topology
(IOP Publishing, 2011)We present multi-epoch radio and optical observations of the M7 dwarf 2MASS J13142039+1320011. We detect a ∼ 1 mJy source at 1.43, 4.86, 8.46 and 22.5 GHz, making it the most luminous radio emission over the widest frequency ... -
Quasi-Quiescent Radio Emission From the First Radio-Emitting T Dwarf
(IOP Publishing, 2013)Radio detections of ultracool dwarfs provide insight into their magnetic fields and the dynamos that maintain them, especially at the very bottom of the main sequence, where other activity indicators dramatically weaken. ... -
The Radio Activity-Rotation Relation of Ultracool Dwarfs
(IOP Publishing, 2012)We present a new radio survey of about 100 late-M and L dwarfs undertaken with the Very Large Array (VLA). The sample was chosen to explore the role of rotation in the radio activity of ultracool dwarfs. As part of the ... -
The Rotation Period and Magnetic Field of the T Dwarf 2massi J1047539+212423 Measured From Periodic Radio Bursts
(IOP Publishing, 2015)Periodic radio bursts from very low mass stars and brown dwarfs simultaneously probe their magnetic and rotational properties. The brown dwarf 2MASSI J1047539+212423 (2M 1047+21) is currently the only T dwarf (T6.5) detected ... -
Simultaneous multi-wavelength observations of magnetic activity in ultracool dwarfs. III. X-ray, radio, and Hα activity trends in M and L dwarfs
(IOP Publishing, 2009)As part of our on-going investigation into the magnetic field properties of ultracool dwarfs, we present simultaneous radio, X-ray, and Hα observations of three M9.5-L2.5 dwarfs (BRI 0021-0214, LSR060230.4+391059, and 2MASS ... -
Trends in Ultracool Dwarf Magnetism. I. X-Ray Suppression and Radio Enhancement
(IOP Publishing, 2014)Although ultracool dwarfs (UCDs) are now known to generate and dissipate strong magnetic fields, a clear understanding of the underlying dynamo is still lacking. We have performed X-ray and radio observations of seven UCDs ... -
VLBI for Gravity Probe B. I. Overview
(IOP Publishing, 2012)We describe the NASA/Stanford gyroscope relativity mission, Gravity Probe B (GP-B), and provide an overview of the following series of six astrometric and astrophysical papers that report on our radio observations and ...