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Related papers: Evolutionary models for ultracool dwarfs

200 papers

Ultra-cool dwarfs of the L spectral type (Teff=1400-2200K) are known to have dusty atmospheres. Asymmetries of the dwarf surface may arise from rotationally-induced flattening and dust-cloud coverage, and may result in non-zero linear…

Solar and Stellar Astrophysics · Physics 2015-05-13 B. Goldman , J. Pitann , M. R. Zapatero Osorio , C. A. L. Bailer-Jones , V. J. S. Bejar , J. A. Caballero , Th. Henning

We review recent advancements in modeling the stellar to substellar transition. The revised molecular opacities, solar oxygen abundances and cloud models allow to reproduce the photometric and spectroscopic properties of this transition to…

Solar and Stellar Astrophysics · Physics 2013-03-01 F. Allard , D. Homeier , B. Freytag , W. Schaffenberger , A. S. Rajpurohit

We use 1-m class telescopes and the Transiting Exoplanet Survey Satellite (TESS) to explore the photometric variability of all known rapidly rotating ($v\sin{i}\gtrsim30$ km\,s$^{-1}$) ultra-cool ($\geq$M7) dwarfs brighter than…

Solar and Stellar Astrophysics · Physics 2023-02-01 Paulo A. Miles-Páez , Stanimir A. Metchev , Benjamin George

Extrasolar planet searches targeting very low-mass stars and brown dwarfs are hampered by intrinsic or instrumental limitations. Time series of astrometric measurements with precisions better than one milli-arcsecond can yield new evidence…

Solar and Stellar Astrophysics · Physics 2014-05-08 J. Sahlmann , P. F. Lazorenko , D. Segransan , E. L. Martin , M. Mayor , D. Queloz , S. Udry

The spectra of brown dwarfs are key to exploring the chemistry and physics that take place in their atmospheres. Late-T dwarf spectra are particularly diagnostic due to their relatively cloud-free atmospheres and deep molecular bands. With…

We present a new set of cooling models and isochrones for both H- and He-atmosphere white dwarfs, incorporating accurate boundary conditions from detailed model atmosphere calculations, and carbon-oxygen chemical abundance profiles based on…

Solar and Stellar Astrophysics · Physics 2015-05-18 M. Salaris , S. Cassisi , A. Pietrinferni , P. M. Kowalski , J. Isern

Astrometric observations of resolved binaries provide estimates of orbital periods and will eventually lead to measurement of dynamical masses. Only a few very low mass star and brown dwarf masses have been measured to date, and the…

We compare eighteen binary systems with precisely determined radii and masses from 23 to 1.1 M_sol, and stellar evolution models produced with our newly revised code TYCHO. ``Overshooting'' and rotational mixing were suppressed in order to…

Astrophysics · Physics 2009-11-06 P. A. Young , E. E. Mamajek , David Arnett , James Liebert

We present full evolutionary calculations appropriate for the study of hydrogen-rich DA white dwarfs. This is done by evolving white dwarf progenitors from the zero age main sequence, through the core hydrogen burning phase, the helium…

We present a new method that investigates the evolutionary history of the pulsating DB white dwarf GD358 using asteroseismology. This is done considering the internal C/O profile, which describes the relative abundances of carbon and oxygen…

Astrophysics · Physics 2008-02-15 J. M. Gonzalez Perez , T. S. Metcalfe

In this work, we identify 734 ultracool dwarfs with a spectral type of M6 or later, including one L0. Of this sample, 625 were studied spectroscopically for the first time. All of these ultracool dwarfs are within 360~pc, with a…

Solar and Stellar Astrophysics · Physics 2022-04-20 You-Fen Wang , A-Li Luo , Wen-Ping Chen , Hugh R. A. Jones , Bing Du , Yin-Bi Li , Shuo Zhang , Zhong-Rui Bai , Xiao Kong , Yan-Xin Guo

Cles is an evolution code recently developed to produce stellar models meeting the specific requirements of studies in asteroseismology. It offers the users a lot of choices in the input physics they want in their models and its versatility…

Astrophysics · Physics 2009-06-23 R. Scuflaire , S. Theado , J. Montalban , A. Miglio , P. -O. Bourge , M. Godart , A. Thoul , A. Noels

Future instruments like NIRCam and MIRI on JWST or METIS at the ELT will be able to image exoplanets that are too faint for current direct imaging instruments. Evolutionary models predicting the planetary intrinsic luminosity as a function…

Eclipsing binaries are important benchmark objects to test and calibrate stellar structure and evolution models. This is especially true for binaries with a fully convective M-dwarf component for which direct measurements of these stars'…

Eclipsing close double white dwarf (WD) systems provide a unique opportunity to directly constrain hydrogen-envelope retention and test common-envelope (CE) evolution in low-mass stars, since they allow precise determinations of stellar…

Context. Being the most numerous and oldest stars in the galaxy, M dwarfs are objects of great interest for exoplanet searches. The presence of molecules in their atmosphere complicates our understanding of their atmospheric properties. But…

Solar and Stellar Astrophysics · Physics 2019-02-20 A. S. Rajpurohit , F. Allard , S. Rajpurohit , R. Sharma , G. D. C. Teixeira , O. Mousis , R. Kamlesh

Studying exoplanets with their parent stars is crucial to understand their population, formation and history. We review some of the key questions regarding their evolution with particular emphasis on giant gaseous exoplanets orbiting close…

Solar and Stellar Astrophysics · Physics 2015-06-23 Tristan Guillot , Douglas N. C. Lin , Pierre Morel , Mathieu Havel , Vivien Parmentier

Surveys for nearby low-luminosity dwarfs tend to avoid the crowded regions of the Galactic Plane. We have devised near-infrared colour-magnitude and colour-colour selection criteria designed to identify late-type M and early-type L dwarfs…

Astrophysics · Physics 2009-11-10 I. Neill Reid

Many low-mass white dwarfs are being discovered in the field of our galaxy and some of them exhibit $g$-mode pulsations, comprising the extremely low-mass variable (ELMV) stars class. Despite it is generally believed that these stars are…

Solar and Stellar Astrophysics · Physics 2018-09-26 L. M. Calcaferro , A. H. Córsico , L. G. Althaus , A. D. Romero , S. O. Kepler

In this paper, we derive the fundamental properties of 1SWASPJ011351.29+314909.7 (J0113+31), a metal-poor (-0.40 +/- 0.04 dex), eclipsing binary in an eccentric orbit (~0.3) with an orbital period of ~14.277 d. Eclipsing M dwarfs orbiting…