Radio Emission from Ultra-Cool Dwarfs

@article{Williams2017RadioEF,
  title={Radio Emission from Ultra-Cool Dwarfs},
  author={P. K. G. Williams},
  journal={arXiv: Solar and Stellar Astrophysics},
  year={2017}
}
  • P. Williams
  • Published 2017
  • Physics
  • arXiv: Solar and Stellar Astrophysics
The 2001 discovery of radio emission from ultra-cool dwarfs (UCDs), the very low-mass stars and brown dwarfs with spectral types of ~M7 and later, revealed that these objects can generate and dissipate powerful magnetic fields. Radio observations provide unparalleled insight into UCD magnetism: detections extend to brown dwarfs with temperatures <1000 K, where no other observational probes are effective. The data reveal that UCDs can generate strong (kG) fields, sometimes with a stable dipolar… Expand

Figures and Tables from this paper

Exoplanet transits with next-generation radio telescopes
Nearly everything we know about extrasolar planets to date comes from optical astronomy. While exoplanetary aurorae are predicted to be bright at low radio frequencies (< 1 GHz), we consider theExpand
Radio Stars: From kHz to THz
  • L. Matthews
  • Physics
  • Publications of the Astronomical Society of the Pacific
  • 2018
Advances in technology and instrumentation have now opened up virtually the entire radio spectrum to the study of stars. An international workshop "Radio Stars: from kHz to THz" was held at theExpand
Direct Radio Discovery of a Cold Brown Dwarf
Magnetospheric processes seen in gas-giants such as aurorae and circularly-polarized cyclotron maser radio emission have been detected from some brown dwarfs. However, previous radio observationsExpand

References

SHOWING 1-10 OF 107 REFERENCES
Discovery of radio emission from the brown dwarf LP944-20
TLDR
It is shown that LP944-20 has an unusually weak magnetic field in comparison to active M-dwarf stars, which might explain the previous null optical and X-rays results, as well as the strength of the radio emissions compared to those at X-ray wavelengths. Expand
STEADY AND TRANSIENT RADIO EMISSION FROM ULTRACOOL DWARFS
We present the results of multi-frequency radio observing campaigns designed to elucidate the nature of radio emission from very low mass stars. We detect radio emission in an additional two epochsExpand
TRENDS IN ULTRACOOL DWARF MAGNETISM. I. X-RAY SUPPRESSION AND RADIO ENHANCEMENT
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 radioExpand
COMPARATIVE ANALYSIS OF TWO FORMATION SCENARIOS OF BURSTY RADIO EMISSION FROM ULTRACOOL DWARFS
Recently, a number of ultracool dwarfs have been found to produce periodic radio bursts with high brightness temperature and polarization degree; the emission properties are similar to the auroralExpand
A Survey for Hα Emission from Late L Dwarfs and T Dwarfs
Recently, studies of brown dwarfs have demonstrated that they possess strong magnetic fields and have the potential to produce radio and optical auroral emissions powered by magnetospheric currents.Expand
Stellar Radio Astronomy: Probing Stellar Atmospheres from Protostars to Giants
▪ Abstract Radio astronomy has provided evidence for the presence of ionized atmospheres around almost all classes of nondegenerate stars. Magnetically confined coronae dominate in the cool half ofExpand
CONFIRMATION OF THE ELECTRON CYCLOTRON MASER INSTABILITY AS THE DOMINANT SOURCE OF RADIO EMISSION FROM VERY LOW MASS STARS AND BROWN DWARFS
We report on radio observations of the M8.5 dwarf LSR J1835+3259 and the L3.5 dwarf 2MASS J00361617+1821104, which provide the strongest evidence to date that the electron cyclotron maser instabilityExpand
THE FIRST MILLIMETER DETECTION OF A NON-ACCRETING ULTRACOOL DWARF
The well-studied M9 dwarf TVLM513–46546 is a rapid rotator (P 2 rot ~ hr) hosting a stable, dipolar magnetic field of ∼3 kG surface strength. Here we report its detection with ALMA at 95 GHz at aExpand
PERIODIC BURSTS OF COHERENT RADIO EMISSION FROM AN ULTRACOOL DWARF
We report the detection of periodic (p = 1.96 hr) bursts of extremely bright, 100% circularly polarized, coherent radio emission from the M9 dwarf TVLM 513-46546. Simultaneous photometric monitoringExpand
JVLA Observations of Young Brown Dwarfs
We present sensitive 3.0 cm JVLA radio continuum observations of six regions of low-mass star formation that include twelve young brown dwarfs and four young brown dwarf candidates. We detect a totalExpand
...
1
2
3
4
5
...