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Related papers: Sporadic Long-term Variability in Radio Activity f…

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We present multi-epoch astrometric observations of the M9 ultra-cool dwarf TVLM513-46546 that is placed at the brown dwarf boundary. The new observations have been performed with the European VLBI Network (EVN) at 6cm band. The target has…

Solar and Stellar Astrophysics · Physics 2017-01-18 Marcin P. Gawronski , Krzysztof Gozdziewski , Krzysztof Katarzynski

We describe our second installment of the 4.75 GHz survey of ultracool dwarfs (UCDs) conducted with the Arecibo radio telescope, which has observed 27 such objects and resulted in the detection of sporadic flaring from the T6 dwarf, WISEPC…

Solar and Stellar Astrophysics · Physics 2016-10-26 Matthew Route , Alexander Wolszczan

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 new results from a continuing 5 GHz search for flaring radio emission from a sample of L and T brown dwarfs, conducted with the 305-m Arecibo radio telescope. In addition to the previously reported flaring from the T6.5-dwarf…

Solar and Stellar Astrophysics · Physics 2016-04-18 Matthew Route , Alexander Wolszczan

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

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

We report on the results of an I-band photometric variability survey of eighteen L dwarfs. We find that seven exhibit statistically significant variations above the 95.4% confidence level with root-mean-square scatter (including photometric…

*Abbreviated abstract* Context: Brown dwarfs in the spectral range L9-T3.5, within the so called L/T transition, have been shown to be variable at higher amplitudes and with greater frequency than other field dwarfs. [...] Now, more…

Earth and Planetary Astrophysics · Physics 2019-11-04 Simon C. Eriksson , Markus Janson , Per Calissendorff

A sample of 123 radio sources that exhibit significant variations at 1.4 GHz on a seven year base-line has been created using FIRST VLA B-array data from 1995 and 2002 on a strip at dec=0 near the south Galactic cap. This sample spans the…

Astrophysics · Physics 2009-11-10 W. H. de Vries , R. H. Becker , R. L. White , D. J. Helfand

We report the detection of periodic (p = 1.96 hours) bursts of extremely bright, 100% circularly polarized, coherent radio emission from the M9 dwarf TVLM 513-46546. Simultaneous photometric monitoring observations have established this…

The paper presents the results of multi-wave radio observations of sixteen red dwarfs with Earth-like planets in the habitable zones on RATAN-600. In the passage mode, radiometers of four frequency ranges of 22, 11, 4.7 and 2.3 GHz (1.38,…

Solar and Stellar Astrophysics · Physics 2025-05-21 Grigory M. Beskin , Vladimir N. Chernenkov , Nikolai N. Bursov , Alexey A. Shlyapnikov , Alexander D. Panov

The Very Large Array was used to observe the ultracool, rapidly rotating M9 dwarf TVLM 513-46546 simultaneously at 4.88 GHz and 8.44 GHz. The radio emission was determined to be persistent, variable and periodic at both frequencies with a…

Astrophysics · Physics 2008-11-26 G. Hallinan , A. Antonova , J. G. Doyle , S. Bourke , W. F. Brisken , A. Golden

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 at radio…

Solar and Stellar Astrophysics · Physics 2015-08-05 P. K. G. Williams , E. Berger

We have undertaken a differential photometric I band search for variability in three Pleiades brown dwarfs and three very low mass field L dwarfs. Analysis of the resultant time series for the Pleiades brown dwarfs (Teide 1, Calar 3, Roque…

Astrophysics · Physics 2007-05-23 C. A. L. Bailer-Jones , R. Mundt

The Deeper, Wider, Faster (DWF) program coordinates observations with telescopes across the electromagnetic spectrum, searching for transients on timescales of milliseconds to days. The tenth DWF observing run was carried out in near…

We have conducted a photometric monitoring program of 3 field late-L brown dwarfs looking for evidence of non-axisymmetric structure or temporal variability in their photospheres. The observations were performed using Spitzer/IRAC 4.5 and 8…

Over the past few years monitoring programs have shown ultra cool dwarfs (UCDs) to be photometrically variable. Of the 60 sources monitored in the field and some 120 monitored in clusters, about 40% show variability in both cases. For mid…

Astrophysics · Physics 2007-05-23 C. A. L. Bailer-Jones

Photometric I band light curves of 21 ultra cool M and L dwarfs are presented. Variability with amplitudes of 0.01 to 0.055 magnitudes (RMS) with typical timescales of an hour to several hours are discovered in half of these objects.…

Astrophysics · Physics 2007-05-23 C. A. L. Bailer-Jones

We report CCD photometric monitoring of the nonemission ultracool dwarf BRI 0021-0214 (M9.5) obtained during 10 nights in 1995 November and 4 nights in 1996 August, with CCD cameras at 1 m class telescopes on the observatories of the Canary…

Astrophysics · Physics 2009-11-06 E. L. Martin , M. R. Zapatero Osorio , H. J. Lehto

The spectra of fast radio bursts (FRBs) encode valuable information about the source's local environment, underlying emission mechanism(s), and the intervening media along the line of sight. We present results from a long-term…

High Energy Astrophysical Phenomena · Physics 2021-01-06 Aaron B. Pearlman , Walid A. Majid , Thomas A. Prince , Kenzie Nimmo , Jason W. T. Hessels , Charles J. Naudet , Jonathon Kocz