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Related papers: Volume-limited radio survey of ultracool dwarfs

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[Abridged] We present a new radio survey of about 100 late-M and L dwarfs undertaken with the VLA. The sample was chosen to explore the role of rotation in the radio activity of ultracool dwarfs. Combining the new sample with results from…

Solar and Stellar Astrophysics · Physics 2015-05-30 M. McLean , E. Berger , A. Reiners

We detect radio emission in an additional two epochs of the ultracool dwarf binary LP 349- 25, finding that the observed emission is broadband and steady on timescales between 10s and 10.7 hours, as well as on timescales of 0.6 and 1.6…

Solar and Stellar Astrophysics · Physics 2009-07-24 R. A. Osten , N. Phan-Bao , S. L. Hawley , I. Neill Reid , R. Ojha

A selection of ultracool dwarfs are known to be radio active, with both gyrosynchrotron emission and the electron cyclotron maser instability being given as likely emission mechanisms. To explore whether ultracool dwarfs previously…

Astrophysics · Physics 2009-11-13 A. Antonova , J. G. Doyle , G. Hallinan , S. Bourke , A. Golden

Observations of radio emission in about 10 per cent of ultra-cool dwarfs (UCDs) indicate the presence of strong, persistent magnetic fields in these stars. These results are in contrast to early theoretical expectations on fully-convective…

Solar and Stellar Astrophysics · Physics 2018-11-26 Andrew Zic , Christene Lynch , Tara Murphy , David L. Kaplan , Poonam Chandra

We report the results of a volume-limited survey using the Australia Telescope Compact Array to search for transient and quiescent radio emission from 15 southern hemisphere ultracool dwarfs. We detect radio emission from 2MASSW…

Solar and Stellar Astrophysics · Physics 2016-01-11 C. Lynch , T. Murphy , V. Ravi , G. Hobbs , K. Lo , C. Ward

We present 325 MHz (90 cm wavelength) radio observations of ultracool dwarfs TVLM 513-46546 and 2MASS J0036+1821104 using the Very Large Array (VLA) in June 2007. Ultracool dwarfs are expected to be undetectable at radio frequencies, yet…

Solar and Stellar Astrophysics · Physics 2012-01-31 T. R. Jaeger , R. A. Osten , T. J. Lazio , N. Kassim , R. L. Mutel

A fraction of very low mass stars and brown dwarfs are known to be radio active, in some cases producing periodic pulses. Extensive studies of two such objects have also revealed optical periodic variability and the nature of this…

Solar and Stellar Astrophysics · Physics 2015-06-17 Leon K. Harding , Gregg Hallinan , Richard P. Boyle , Aaron Golden , Navtej Singh , Brendan Sheehan , Robert T. Zavala , Ray F. Butler

We present a generalized analytical Bayesian framework for calculating the occurrence rate of steady emission (or absorption) in astrophysical objects. As a proof-of-concept, we apply this framework to non-flaring quiescent radio emission…

Solar and Stellar Astrophysics · Physics 2023-08-02 Melodie M. Kao , Evgenya L. Shkolnik

[Abridged] As part of our on-going investigation into the magnetic field properties of ultracool dwarfs, we present simultaneous radio, X-ray, and H-alpha observations of three M9.5-L2.5 dwarfs (BRI0021-0214, LSR060230.4+391059, and…

Solar and Stellar Astrophysics · Physics 2014-11-20 E. Berger , G. Basri , T. A. Fleming , M. S. Giampapa , J. E. Gizis , J. Liebert , E. L. Martin , N. Phan-Bao , R. E. Rutledge

The well-studied M9 dwarf TVLM 513-46546 is a rapid rotator (P_rot ~ 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 $56 \pm 12$ uJy,…

Solar and Stellar Astrophysics · Physics 2015-12-11 P. K. G. Williams , S. L. Casewell , C. R. Stark , S. P. Littlefair , Ch. Helling , E. Berger

We explore the radio emission from the M9 dwarf, TVLM513-46546, at multiple radio frequencies, determining the flux spectrum of persistent radio emission, as well as constraining the levels of circular polarization. Detections at both 3.6…

Astrophysics · Physics 2009-11-13 Rachel A. Osten , Suzanne L. Hawley , Timothy S. Bastian , I. Neill Reid

We present radio observations of a comprehensive sample of 90 dwarf stars and brown dwarfs ranging from spectral type M5 to T8. We detect three radio active sources in addition to the six objects previously detected in quiescence and…

Astrophysics · Physics 2008-11-26 Edo Berger

Radio activity has been observed in a large variety of stellar objects, including in the last few years, ultra-cool dwarfs. To explore the extent of long-term radio activity in ultra-cool dwarfs, we use data taken over an extended period of…

Astrophysics · Physics 2009-11-13 A. Antonova , J. G. Doyle , G. Hallinan , A. Golden , C. Koen

With the improvements in radio interferometry sensitivity, the quest for coherent radio emission from exoplanets and ultra-cool dwarfs, which is indicative of their magnetic fields, has gained significant momentum in recent years. We…

[Abridged] As part of our on-going investigation of magnetic activity in ultracool dwarfs we present simultaneous radio, X-ray, UV, and optical observations of LSR1835+32 (M8.5), and simultaneous X-ray and UV observations of VB10 (M8), both…

We present a 20-pc, volume-limited sample of M7-L8 dwarfs created through spectroscopic follow-up of sources selected from the Two Micron All Sky Survey (2MASS) Second Incremental Release Point Source Catalog. In this paper, we present…

Empirical trends in stellar X-ray and radio luminosities suggest that low mass ultracool dwarfs (UCDs) should not produce significant radio emission. Defying these expectations, strong non-thermal emission has been observed in a few UCDs in…

Solar and Stellar Astrophysics · Physics 2021-07-16 A. G. Hughes , A. C. Boley , R. A. Osten , J. A. White , M. Leacock

Magnetically driven phenomena such as flaring events and aurorae lead ultracool dwarfs to emit at radio frequencies. Despite decades of scrutiny, a comprehensive physical understanding of their radio emission at different frequencies…

Solar and Stellar Astrophysics · Physics 2026-03-17 Michele L. Silverstein , Tracy E. Clarke , Wendy M. Peters , Emil Polisensky , Jackie Villadsen , Jordan M. Stone

[Abridged] We present the first simultaneous radio, X-ray, ultraviolet, and optical spectroscopic observations of the M8.5 dwarf TVLM513-46546, with a duration of 9 hours. These observations are part of a program to study the origin of…

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 range detected…

Solar and Stellar Astrophysics · Physics 2015-05-28 M. McLean , E. Berger , J. Irwin , J. Forbrich , A. Reiners
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