相关论文: Benchmarking Substellar Evolutionary Models Using …

We present the first parallax and luminosity measurements for an L subdwarf, the sdL7 2MASS J05325346+8246465. Observations conducted over three years by the USNO infrared astrometry program yield an astrometric distance of 26.7+/-1.2 pc…

We report the discovery of a bright, brown dwarf companion to the star HIP 64892, imaged with VLT/SPHERE during the SHINE exoplanet survey. The host is a B9.5V member of the Lower-Centaurus-Crux subgroup of the Scorpius Centaurus OB…

We conduct a statistical analysis of a combined sample of direct imaging data, totalling nearly 250 stars. The stars cover a wide range of ages and spectral types, and include five detections ($\kappa$ And b, two $\sim$60 M$_{\rm J}$ brown…

(Abridged) We present Keck, HST, and Gemini-North observations of the L4+L4 binary HD 130948BC which together span ~70% of the binary's orbital period. We determine a total dynamical mass of 0.109+/-0.002 Msun (114+/-2 Mjup). The flux ratio…

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,…

Procyon is a great system to probe stellar evolution of non-interacting binaries. We present an extensive grid of MESA (Modules for Experiments in Stellar Astrophysics) evolutionary tracks to constrain the evolution of Procyon A and B. We…

Studies of fundamental parameters of very low-mass objects are indispensable to provide tests of stellar evolution models that are used to derive theoretical masses of brown dwarfs and planets. However, only objects with dynamically…

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…

We derive the optical luminosity, colors, and ratios of the blue and red helium burning (HeB) stellar populations from archival Hubble Space Telescope observations of nineteen starburst dwarf galaxies and compare them with theoretical…

We present 2.9-4.1 micron integral field spectroscopy of the L4+L4 brown dwarf binary HD 130948BC, obtained with the Arizona Lenslets for Exoplanet Spectroscopy (ALES) mode of the Large Binocular Telescope Interferometer (LBTI). The HD…

We present two confirmed wide separation L-dwarf common proper motion companions to nearby stars and one candidate identified from the Two Micron All Sky Survey. Spectral types from optical spectroscopy are L0 V, L2.5 V, and L8 V.…

Benchmark brown dwarfs are those objects for which fiducial constraints are available, including effective temperature, parallax, age, metallicity. We searched for new cool brown dwarfs in 186 sq.deg. of the new area covered by the data…

We present new $H$ (1.5-1.8 $\mu$m) photometric and $K_1$ (1.9-2.2 $\mu$m) spectroscopic observations of the young exoplanet HD 95086 b obtained with the Gemini Planet Imager. The $H$-band magnitude has been significantly improved relative…

In the past years, some extremely red brown dwarfs were found. They were believed to have low surface gravity, but many of their spectral characteristics were similar to those of high surface gravity brown dwarfs, showing that youth (or low…

We present the current status of the analytic theory of brown dwarf evolution and the lower mass limit of the hydrogen burning main sequence stars. In the spirit of a simplified analytic theory we also introduce some modifications to the…

We present the results of a survey for stellar and substellar companions to 82 young stars in the nearby OB association Upper Scorpius. This survey used nonredundant aperture-mask interferometry to achieve typical contrast limits of…

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 LBTI/ALES 3.07-4.08 micron spectroscopic observations of HD~33632~Ab, a ~53 M_Jup directly imaged companion to an F8 star. Spectroscopic measurements of HD 33632 Ab now span 1-4 micron, and we perform the first spectroscopic…

Use of the highly sensitive Hokupa'a curvature wavefront sensor has allowed for the first time direct adaptive optics (AO) guiding on brown dwarfs and VLM stars (SpT=M7-L2). An initial survey of 9 such objects discovered one 0.15" binary…

We present a large forward-modeling analysis for 55 late-T (T7-T9) dwarfs, using low-resolution ($R\approx150$) near-infrared spectra and cloudless Sonora-Bobcat model atmospheres. We derive the objects' effective temperatures, surface…