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Related papers: Correlated spectral variability in brown dwarfs

200 papers

We present a new analysis of the spectroscopic variability of WISE~J104915.57$-$531906.1AB (WISE~1049AB, L7.5+T0.5), observed using the NIRSpec instrument onboard the James Webb Space Telescope (GO 2965 - PI: Biller). We explored the…

We present K- and L-band photometry obtained with the Keck I telescope for a representative sample of L and T dwarfs. These observations were motivated in part by the dominant role water and methane play in shaping the flux near 2 and 3…

Astrophysics · Physics 2009-11-06 D. C. Stephens , M. S. Marley , K. S. Noll , N. Chanover

Amid rapid advances in time-domain astronomy, multi-wavelength (e.g., optical and infrared) time-domain studies of quasars remain scarce. Here we present a systematic analysis of four quasars initially selected by their Ks-band variability…

Astrophysics of Galaxies · Physics 2025-10-31 Lin Long , Zhen-ya Zheng , Ning Jiang , Chun Xu , Jiaqi Lin , Fang-Ting Yuan , Chunyan Jiang , Ruqiu Lin , Hai-Cheng Feng , Hengxiao Guo , Xiang Ji

We present a UVES/VLT high resolution atlas of three L dwarfs and one T dwarf system, spectral classes at which most of the objects are brown dwarfs. Our atlas covers the optical region from H$\alpha$ up to the near infrared at 1 $\mu$m. We…

Astrophysics · Physics 2009-11-13 A. Reiners , D. Homeier , P. H. Hauschildt , F. Allard

We present results from the "Weather on Other Worlds" Spitzer Exploration Science program to investigate photometric variability in L and T dwarfs, usually attributed to patchy clouds. We surveyed 44 L3-T8 dwarfs, spanning a range of…

The determination of the brown dwarf binary fraction may contribute to the understanding of the substellar formation mechanisms. Unresolved brown dwarf binaries may be revealed through their peculiar spectra or the discrepancy between…

Solar and Stellar Astrophysics · Physics 2015-11-18 E. Manjavacas , B. Goldman , J. M. Alcalá , M. R. Zapatero-Osorio , V. J. S. Béjar , D. Homeier , M. Bonnefoy , R. L. Smart , T. Henning , F. Allard

We use new and published medium resolution 0.6--2.5 $\mu$m spectra of L and T dwarfs to develop a unified classification system for both of these new spectral classes. Two indices of the system at 1.2 $\mu$m and 1.5 $\mu$m are based on…

Astrophysics · Physics 2007-05-23 T. R. Geballe , G. R. Knapp , S. K. Leggett , X. Fan , D. A. Golimowski

Constraining L dwarf properties from their spectra is challenging. Near-infrared spectra probe a limited range of pressures, while many species condense within their photospheres. Condensation creates two complexities: gas-phase species…

Solar and Stellar Astrophysics · Physics 2023-04-19 Melanie Rowland , Caroline Morley , Michael Line

Brown dwarfs that are short period ($<10\,$day) companions to actively flaring M dwarfs may provide a context to directly observe flare-driven photochemistry and structural changes in an extrasolar planet-like atmosphere. To assess the…

Solar and Stellar Astrophysics · Physics 2025-09-10 Aidan Gibbs , Michael P. Fitzgerald

We present the discovery of five late-type T dwarfs identified with the Wide-field Infrared Survey Explorer (WISE). Low-resolution near-infrared spectroscopy obtained with the Magellan Folded-port InfraRed Echellette (FIRE) reveal strong…

We present an analysis of long-term photometric variability for nearby red dwarfs at optical wavelengths. The sample consists of 264 M dwarfs south of DEC = +30 with V-K = 3.96-9.16 and Mv~10-20 (spectral types M2V-M8V), most of which are…

Benchmark brown dwarfs in wide binary systems are crucial for characterizing substellar objects and calibrating atmospheric and evolutionary models. However, brown dwarf benchmarks with subsolar metallicity, very cool temperatures, or…

We report the discovery of 87 new T dwarfs uncovered with the Wide-field Infrared Survey Explorer (WISE) and three brown dwarfs with extremely red near-infrared colors that exhibit characteristics of both L and T dwarfs. Two of the new T…

We report parallax measurements for 70 ultracool dwarfs (UCDs). Using both literature values and our sample, we report new polynomial relations between spectral type and M$_{JHK}$. Including resolved L/T transition binaries in the…

Only a handful of late-T brown dwarfs have been monitored for spectro-photometric variability, leaving incomplete the study of the atmospheric cloud structures of the coldest brown dwarfs, that share temperatures with some cold,…

Solar and Stellar Astrophysics · Physics 2022-07-27 Elena Manjavacas , Theodora Karalidi , Xianyu Tan , Johanna M. Vos , Ben W. P. Lew , Beth A. Biller , Natalia Oliveros-Gomez

M dwarfs are active stars that exhibit variability in chromospheric emission and photometry at short and long timescales, including long cycles that are related to dynamo processes. This activity also impacts the search for exoplanets…

Solar and Stellar Astrophysics · Physics 2023-07-19 L. Mignon , N. Meunier , X. Delfosse , X. Bonfils , N. C. Santos , T. Forveille , G. Gaisné , N. Astudillo-Defru , C. Lovis , S. Udry

Archival data from the WISE satellite reveals infrared flux variations of tens of per cent around numerous dusty white dwarfs. Data spanning more than seven years reveal more than half of known systems are varying in the 3.4 micron band,…

Solar and Stellar Astrophysics · Physics 2019-02-13 Andrew Swan , Jay Farihi , Thomas G. Wilson

We present the current status of PHOENIX model atmospheres for dwarfs of the spectral type T, typical for older field brown dwarfs and low-mass brown dwarfs. The results are based on new predictions of the CH_4 line opacities from…

Astrophysics · Physics 2007-05-23 D. Homeier , P. H. Hauschildt , F. Allard

Near-infrared spectroscopic observations of a sample of very cool, low-mass objects are presented with higher spectral resolution than in any previous studies. Six of the objects are L-dwarfs, ranging in spectral class from L2 to L8/9, and…

Using the Subaru Telescope, we have obtained multiple near-infrared spectra of the cool brown dwarf, SDSS 1624+00, in search of spectral variability in an 80 minute time span. We have found the suspected variability of water vapor…