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Related papers: Methane Emission From a Cool Brown Dwarf

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We present the discovery of a companion to the Y-dwarf, CWISEP J193518.59-154620.3, the second Y-Y dwarf binary detected to date. Y-dwarfs are the coldest known free-floating objects ($<$ 500 K) and on average represent the lowest mass…

The coldest brown dwarf, WISE 0855, is the closest known planetary-mass, free-floating object and has a temperature nearly as cold as the solar system gas giants. Like Jupiter, it is predicted to have an atmosphere rich in methane, water,…

Radiation belts are present in all large-scale Solar System planetary magnetospheres: Earth, Jupiter, Saturn, Uranus, and Neptune. These persistent equatorial zones of trapped high energy particles up to tens of MeV can produce bright radio…

Earth and Planetary Astrophysics · Physics 2024-03-15 Melodie M. Kao , Amy J. Mioduszewski , Jackie Villadsen , Evgenya L. Shkolnik

We present mid-infrared spectroscopy of Jupiter's mid-to-high latitudes using Gemini-North/TEXES (Texas Echelon Cross Echelle Spectrograph) on March 17-19, 2017. These observations capture Jupiter's hydrocarbon auroral emissions before,…

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 observations targeted known brown dwarfs discovered via…

Brown dwarfs display Jupiter-like auroral phenomena such as magnetospheric H$\alpha$ emission and coherent radio emission. Coherent radio emission is a probe of magnetospheric acceleration mechanisms and provides a direct measurement of the…

Solar and Stellar Astrophysics · Physics 2023-07-12 H. K. Vedantham , Trent J. Dupuy , E. L. Evans , A. Sanghi , J. R. Callingham , T. W. Shimwell , W. M. J. Best , M. C. Liu , P. Zarka

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…

With infrared flux contrasts larger than typically seen in hot Jupiter, tidally-locked white dwarf-brown dwarf binaries offer a superior opportunity to investigate atmospheric processes in irradiated atmospheres. NLTT5306 is such a system,…

The coldest Y spectral type brown dwarfs are similar in mass and temperature to cool and warm ($\sim$200 -- 400 K) giant exoplanets. We can therefore use their atmospheres as proxies for planetary atmospheres, testing our understanding of…

Many brown dwarfs are on ultra-short period and tidally-locked orbits around white dwarf hosts. Because of these small orbital separations, the brown dwarfs are irradiated at levels similar to hot Jupiters. Yet, they are easier to observe…

Solar and Stellar Astrophysics · Physics 2021-12-22 Ben W. P. Lew , Dániel Apai , Yifan Zhou , Mark Marley , L. C. Mayorga , Xianyu Tan , Vivien Parmentier , Sarah Casewell , Siyi Xu

WD0137-349 is a white dwarf-brown dwarf binary system in a 116 minute orbit. We present radial velocity observations and multiwaveband photometry from V, R and I in the optical, to J, H and Ks in the near-IR and [3.6], [4.5], [5.8] and…

We present observations of two occultations of the extrasolar planet WASP-33b using the Wide Field Camera 3 (WFC3) on the HST, which allow us to constrain the temperature structure and composition of its dayside atmosphere. WASP-33b is the…

Earth and Planetary Astrophysics · Physics 2015-05-08 Korey Haynes , Avi M. Mandell , Nikku Madhusudhan , Drake Deming , Heather Knutson

The James Webb Space Telescope (JWST) will open up the possibility of comprehensively measuring the emission spectra of rocky exoplanets orbiting M dwarfs to detect and characterize their atmospheres. In preparation for this opportunity, we…

Earth and Planetary Astrophysics · Physics 2019-12-06 Matej Malik , Eliza M. -R. Kempton , Daniel D. B. Koll , Megan Mansfield , Jacob L. Bean , Edwin Kite

Context: Observations of auroral emissions are powerful means to remotely sense the space plasma environment around planetary bodies and ultracool dwarfs. Therefore successful searches and characterization of aurorae outside the Solar…

Radio and X-ray emission from brown dwarfs suggest that an ionised gas and a magnetic field with a sufficient flux density must be present. We perform a reference study for late M-dwarfs, brown dwarfs and giant gas planet to identify which…

Earth and Planetary Astrophysics · Physics 2015-11-04 M. I. Rodriguez-Barrera , Ch. Helling , C. R. Stark , A. M. Rice

A number of ultra-cool dwarfs emit circularly polarised radio waves generated by the electron cyclotron maser instability. In the solar system such radio is emitted from regions of strong auroral magnetic field-aligned currents. We thus…

Solar and Stellar Astrophysics · Physics 2015-06-11 J. D. Nichols , M. R. Burleigh , S. L. Casewell , J. T. Clarke , S. W. H Cowley , A. A. West , G. A. Wynn

A number of fast-rotating ultra cool dwarfs (UCDs) emit pulsed coherent radiation, attributed to the electron cyclotron maser instability, a phenomenon that occurs in the solar system at planets with strong auroral emission. In this paper…

Solar and Stellar Astrophysics · Physics 2017-08-02 Sam Turnpenney , Jonathan Nichols , Graham Wynn , Sarah Casewell

WD J2356$-$209 is a cool metal-polluted white dwarf whose visible spectrum is dominated by a strong and broad sodium feature. Although discovered nearly two decades ago, no detailed and realistic analysis of this star had yet been realized.…

Solar and Stellar Astrophysics · Physics 2019-03-06 S. Blouin , P. Dufour , N. F. Allard , S. Salim , R. M. Rich , L. V. E. Koopmans

The recently discovered brown dwarf WISE 0855 presents our first opportunity to directly study an object outside the Solar System that is nearly as cold as our own gas giant planets. However the traditional methodology for characterizing…

JWST is opening many avenues for exploration. For cold brown dwarfs and exoplanets, JWST has opened the door to the mid-infrared wavelength region, where such objects emit significant energy. For the first time, astronomers have access to…

Solar and Stellar Astrophysics · Physics 2025-01-07 S. K. Leggett , Pascal Tremblin