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The substellar companion HD206893b has recently been discovered by direct imaging of its disc-bearing host star with the SPHERE instrument. We investigate the atypical properties of the companion, which has the reddest near-infrared colours…

The determination of the fundamental properties (mass, separation, age, gravity and atmospheric properties) of brown dwarf companions allows us to infer crucial informations on their formation and evolution mechanisms. Spectroscopy of…

Earth and Planetary Astrophysics · Physics 2020-06-03 D. Mesa , V. D'Orazi , A. Vigan , D. Kitzmann , K. Heng , R. Gratton , S. Desidera , M. Bonnefoy , B. Lavie , A. -L. Maire , S. Peretti , A. Boccaletti

The masses and temperatures of young low mass stars and brown dwarfs in star- forming regions are not yet well established because of uncertainties in the age of individual objects and the spectral type vs. temperature scale appropriate for…

Astrophysics · Physics 2009-11-13 F. C. Riddick , P. F. Roche , P. W. Lucas

This study presents observations of two possible substellar survivors of post-main sequence engulfment, currently orbiting white dwarf stars. Infrared and optical spectroscopy of GD 1400 reveal a 9.98 h orbital period, where the benchmark…

Solar and Stellar Astrophysics · Physics 2022-12-21 N. Walters , J. Farihi , T. R. Marsh , E. Breedt , P. W. Cauley , T. von Hippel , J. J. Hermes

Age is a stellar parameter that is both fundamental and difficult to determine. Among middle-aged M dwarfs, the most prolific hosts of close-in and detectable exoplanets, gyrochronology is the most promising method to assign ages, but…

Earth and Planetary Astrophysics · Physics 2023-02-08 Eric Gaidos , Zachary Claytor , Ryan Dungee , Aleezah Ali , Gregory A. Feiden

Constraining substellar evolutionary models (SSEMs) is particularly difficult due to a degeneracy between the mass, age, and luminosity of a brown dwarf. In cases where a brown dwarf is found as a directly imaged companion to a star, as in…

How planetary systems form and evolve is a key question in astronomy. Revealing how host star properties, such as elemental abundances, age, and mass, differ from those of non-host stars, and how they correlate with planetary…

Solar and Stellar Astrophysics · Physics 2025-11-12 Xunzhou Chen , Tiancheng Sun , Lifei Ye

We report the discovery of a population of late-M and L field dwarfs with unusual optical and near-infrared spectral features that we attribute to low gravity -- likely uncommonly young, low-mass brown dwarfs. Many of these new-found young…

We measure precise orbits and dynamical masses and derive age constraints for six confirmed and one candidate Sirius-like systems, including the Hyades member HD 27483. Our orbital analysis incorporates radial velocities, relative…

Solar and Stellar Astrophysics · Physics 2023-07-11 Hengyue Zhang , Timothy D. Brandt , Rocio Kiman , Alexander Venner , Qier An , Minghan Chen , Yiting Li

Recent studies have shown that close-in brown dwarfs in the mass range 35-55 M$_{\rm Jup}$ are almost depleted as companions to stars, suggesting that objects with masses above and below this gap might have different formation mechanisms.…

Solar and Stellar Astrophysics · Physics 2017-06-07 J. Maldonado , E. Villaver

We report the results of a deep near infrared (JHK) survey of the outer parts of the Trapezium Cluster with Gemini South/Flamingos. 396 sources were detected in a 26 arcmin^2 area, including 138 brown dwarf candidates, defined as M<0.075…

Astrophysics · Physics 2009-11-11 P. W. Lucas , P. F. Roche , M. Tamura

We have estimated the age of the young moving group TW Hydrae Association, a cohort of a few dozen stars and brown dwarfs located near the Sun which share the same kinematic properties and, presumably, the same origin and age. The…

Astrophysics · Physics 2016-07-01 David Barrado y Navascues

The final composition of giant planets formed as a result of gravitational instability in the disk gas depends on their ability to capture solid material (planetesimals) during their 'pre-collapse' stage, when they are extended and cold,…

Earth and Planetary Astrophysics · Physics 2015-05-14 R. Helled , P. Bodenheimer

Under the right conditions brown dwarfs that gain enough mass late in their lives to cross the hydrogen burning limit will not turn into low-mass stars, but rather remain essentially brown dwarf-like. While these objects, called either…

Solar and Stellar Astrophysics · Physics 2022-06-29 Dorsa Majidi , John C. Forbes , Abraham Loeb

The potential existence of a giant planet orbiting within a few AU of a stellar remnant has profound implications for both the survival and possible regeneration of planets during post-main sequence stellar evolution. This paper reports…

Earth and Planetary Astrophysics · Physics 2012-06-15 J. Farihi , J. P. Subasavage , E. P. Nelan , H. C. Harris , C. C. Dahn , J. Nordhaus , D. S. Spiegel

The discovery of 9 new brown-dwarf candidates orbiting stars in the CORALIE and HARPS radial-velocity surveys is reported. New CORALIE radial velocities yielding accurate orbits of 6 previously-known hosts of potential brown-dwarf…

We suggest that Jovian planets will survive the late stages of stellar evolution, and that white dwarfs will retain planetary systems in wide orbits (>5AU). Utilising evolutionary models for Jovian planets, we show that infra-red imaging…

Astrophysics · Physics 2009-11-07 M. R. Burleigh , F. J. Clarke , S. T. Hodgkin

Direct imaging of exoplanetary systems is a powerful technique that can reveal Jupiter-like planets in wide orbits, can enable detailed characterization of planetary atmospheres, and is a key step towards imaging Earth-like planets. Imaging…

Astrophysics · Physics 2009-09-17 C. Marois , B. Macintosh , T. Barman , B. Zuckerman , I. Song , J. Patience , D. Lafreniere , R. Doyon
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