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Related papers: Polarised radio pulsations from a new T dwarf bina…

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Searches for companions of brown dwarfs by direct imaging mainly probe orbital separations > 3-10 AU. On the other hand, previous radial velocity surveys of brown dwarfs are mainly sensitive to separations smaller than 0.6 AU. It has been…

Astrophysics · Physics 2009-11-13 V. Joergens

With the discovery of Y dwarfs by the WISE mission, the population of field brown dwarfs now extends to objects with temperatures comparable to those of Solar System planets. To investigate the atmospheres of these newly identified brown…

Solar and Stellar Astrophysics · Physics 2015-06-23 A. Rajan , J. Patience , P. A. Wilson , J. Bulger , R. J. De Rosa , K. Ward-Duong , C. Morley , F. Pont , R. Windhorst

Cold brown dwarfs are excellent analogs of widely separated, gas giant exoplanets, and provide insight into the potential atmospheric chemistry and physics we may encounter in objects discovered by future direct imaging surveys. We present…

We report the discovery of the first new ultra-cool brown dwarf found with the Wide-field Infrared Survey Explorer (WISE). The object's preliminary designation is WISEPC J045853.90+643451.9. Follow-up spectroscopy with the LUCIFER…

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

Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very bright and highly variable X-ray emission that are believed to be powered by ultra-strong magnetic fields of >1e14 G, according to the 'magnetar' model. The radio…

Low-mass white dwarfs can either be produced in low-mass X-ray binaries by stable mass transfer to a neutron star, or in a common-envelope phase with a heavier white dwarf companion. We have searched 8 low-mass white dwarf candidates…

Astrophysics · Physics 2008-11-26 Joeri van Leeuwen , Robert D. Ferdman , Sol Meyer , Ingrid Stairs

Neutron stars that show X-ray and $\gamma$-ray pulsed emission must, somewhere in the magnetosphere, generate electron-positron pairs. Such pairs are also required for radio emission, but then why do a number of these sources appear radio…

High Energy Astrophysical Phenomena · Physics 2023-04-19 Inés Pastor-Marazuela , Samayra M. Straal , Joeri van Leeuwen , Vlad I. Kondratiev

Radio-loud magnetars are well known for exhibiting rare and unusual radiative properties that are seldom seen in the wider pulsar population. Yet one form of emissive behavior that remains elusive among pulsars and magnetars is narrowband…

High Energy Astrophysical Phenomena · Physics 2026-03-24 Marcus E. Lower , Paul Scholz , Fernando Camilo , David M. Palmer , John E. Reynolds , John M. Sarkissian , Lawrence J. Toomey , George Younes

Radio observations at low frequencies are sensitive to the magnetic activity of stars and the plasma environment surrounding them. The accurate interpretation of the processes underlying the radio signatures requires a detailed…

Solar and Stellar Astrophysics · Physics 2025-11-13 S. Bellotti , P. I. Cristofari , J. R. Callingham , J. Morin , P. Petit , A. A. Vidotto , M. Jardine , L. Arnold , R. D. Kavanagh , J. Llama , H. Vedantham

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

We have monitored photometrically the Y0 brown dwarf WISEP J173835.52+273258.9 (W1738) at both near- and mid-infrared wavelengths. This ~1 Gyr-old 400K dwarf is at a distance of 8pc and has a mass around 5 M_Jupiter. We observed W1738 using…

We present Spitzer IRAC photometry of twelve very late-type T dwarfs; nine have [3.6], [4.5], [5.8] and [8.0] photometry and three have [3.6] and [4.5] photometry only. We investigate trends with type and color for the planning and…

Models of brown dwarf atmospheres suggest they exhibit complex physical behaviour. Observations have shown that they are indeed dynamic, displaying small photometric variations over timescales of hours. Here I report results of infrared…

Astrophysics · Physics 2009-11-13 C. A. L. Bailer-Jones

We have investigated the radio emission from the anomalous X-ray pulsar 1E 1547.0-5408 (PSR J1550-5418) using the Parkes telescope and the Australia Telescope Compact Array. The flux density of the pulsar is roughly the same between 1.4 and…

Astrophysics · Physics 2009-11-13 F. Camilo , J. Reynolds , S. Johnston , J. P. Halpern , S. M. Ransom

We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, high-resolution (R~20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC…

Solar and Stellar Astrophysics · Physics 2015-08-06 L. Prato , G. N. Mace , E. L. Rice , I. S. McLean , J. D. Kirkpatrick , A. J. Burgasser , S. S. Kim

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

Magnetars are young, rotating neutron stars that possess larger magnetic fields ($B$ $\approx$ $10^{13}$-$10^{15}$ G) and longer rotational periods ($P$ $\approx$ 1-12 s) than ordinary pulsars. In contrast to rotation-powered pulsars,…

The NASA Wide-field Infrared Survey Explorer (WISE) has discovered almost all the known members of the new class of Y-type brown dwarfs. Most of these Y dwarfs have been identified as isolated objects in the field. It is known that binaries…

Solar and Stellar Astrophysics · Physics 2016-03-16 Daniela Opitz , C. G. Tinney , Jacqueline Faherty , Sarah Sweet , Christopher R. Gelino , J. Davy Kirkpatrick