相关论文: The discovery of two new benchmark brown dwarfs wi…
We have obtained high contrast images of four nearby, faint, and very low mass objects 2MASSJ04351455-1414468, SDSSJ044337.61+000205.1, 2MASSJ06085283-2753583 and 2MASSJ06524851-5741376 (here after 2MASS0435-14, SDSS0443+00, 2MASS0608-27…
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…
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…
The physical properties of brown dwarf companions found to orbit nearby, solar-type stars can be benchmarked against independent measures of their mass, age, chemical composition, and other parameters, offering insights into the evolution…
Using a simulated disk brown dwarf (BD) population, we find that new large area infrared surveys are expected to identify enough BDs covering wide enough mass--age ranges to potentially measure the mass function down to ~0.03Mo, and the BD…
By definition, brown dwarfs never reach the main-sequence, cooling and dimming over their entire lifetime, thus making substellar models challenging to test because of the strong dependence on age. Currently, most brown dwarfs with…
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 search for the astrometric signatures of planets and brown dwarfs known from radial velocity surveys in the improved Hipparcos intermediate astrometric data provided by van Leeuwen (2007a). Our aim is to put more significant constraints…
We present results from an adaptive optics survey for substellar and stellar companions to Sun-like stars. The survey targeted 266 F5-K5 stars in the 3Myr to 3Gyr age range with distances of 10-190pc. Results from the survey include the…
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…
The extensive timespan of modern radial velocity surveys has made the discovery of long-period substellar companions more common in recent years, however measuring the true masses of these objects remains challenging. Astrometry from the…
Benchmark brown dwarf companions with well-determined ages and model-independent masses are powerful tools to test substellar evolutionary models and probe the formation of giant planets and brown dwarfs. Here, we report the independent…
Long-period brown dwarf companions detected in radial velocity surveys are important targets for direct imaging and astrometry to calibrate the mass-luminosity relation of substellar objects. Through a 20-year radial velocity monitoring of…
We report the detections of a giant planet (MARVELS-7b) and a brown dwarf candidate (MARVELS-7c) around the primary star in the close binary system, HD 87646. It is the first close binary system with more than one substellar circum-primary…
Brown dwarfs with well-measured masses, ages and luminosities provide direct benchmark tests of substellar formation and evolutionary models. We report the first results from a direct imaging survey aiming to find and characterize…
Aims. The project aims to understand better the role of wide brown dwarf companions on planetary systems. Methods. We obtained high-resolution spectra of six bright stars with co-moving wide substellar companions with the SONG, CARMENES,…
Context: So far more than 60 substellar companions have been discovered around giant stars. These systems present physical and orbital properties that contrast to those detected orbiting less evolved stars. Aims: We are conducting a radial…
Tension remains between the observed and modeled properties of substellar objects, but objects in binary orbits, with known dynamical masses can provide a way forward. HD 72946 B is a recently imaged brown dwarf companion to the nearby,…
Context: Brown dwarfs exhibit complex atmospheric signatures, and their properties depend sensitively on effective temperature, surface gravity, and metallicity. Several physical properties of brown dwarfs in binary systems can be well…
We present first results from the Palomar Adaptive Optics Survey of Young Stars conducted at the Hale 5 m telescope. Through direct imaging we have discovered a brown dwarf and two low-mass stellar companions to the young solar-type stars…