相关论文: Binaries among Ultra-cool Dwarfs and Brown Dwarfs

Despite a burgeoning set of ultracool dwarf ($\leq$M7) radio detections, their radio emissions remain enigmatic. Open questions include the plasma source and acceleration mechanisms for the non-auroral "quiescent" component of these…

Binary/multiple status can affect stars at all stages of their lifetimes: evolution onto the main sequence, properties on the main sequence, and subsequent evolution. 5 $M_\odot$ stars have provided a wealth of information about the binary…

The formation mechanisms and chemical compositions of brown dwarfs likely span a diverse range. If they are formed predominantly in isolation by gravitational collapse like dwarf stars then their compositions might follow those of dwarf…

There are no known examples of magnetic white dwarfs with fields larger than about 3MG paired with a non-degenerate companion in detached binary systems. The suggestion is that highly magnetic, isolated white dwarfs may originate from stars…

Astronomical polarimetry is a powerful technique that can provide physical information sometimes difficult or impossible to obtain by any other type of observation. Almost every class of binary star can benefit from polarimetric…

Many binary systems are in a state of strong interaction, where mass exchanges, accretion disks, common envelopes provide circumstellar matter which can have significant effects in microlensing light curves of background sources. Such…

Generic scalar-tensor theories of gravity predict deviations from Newtonian physics inside astrophysical bodies. In this paper, we point out that low mass stellar objects, red and brown dwarf stars, are excellent probes of these theories.…

We present a comprehensive description of the theory and practice of opacity calculations from the infrared to the ultraviolet needed to generate models of the atmospheres of brown dwarfs and extrasolar giant planets. Methods for using…

Ultracool subdwarfs are low luminosity, late-type M and L dwarfs that exhibit spectroscopic indications of subsolar metallicity and halo kinematics. Their recent discovery and ongoing investigation have led to new insights into the role of…

We present results from the first hydrodynamical star formation calculation to demonstrate that brown dwarfs are a natural and frequent product of the collapse and fragmentation of a turbulent molecular cloud. The brown dwarfs form via the…

Clouds of metal-bearing condensates play a critical role in shaping the emergent spectral energy distributions of the coolest classes of low-mass stars and brown dwarfs, L and T dwarfs. Because condensate clouds in planetary atmospheres…

We present four newly validated transiting brown dwarfs identified through TESS photometry and confirmed with high-precision radial velocity measurements obtained from the FEROS and PLATOSpec spectrographs. Notably, three of these…

We have used the NICMOS NIC1 camera on the Hubble Space Telescope to obtain high angular resolution images of 51 ultracool dwarfs in the immediate Solar Neighbourhood. Nine systems are resolved as binary, with component separations from 1.5…

The astrometric space mission Gaia is expected to detect a large number of brown dwarf binary systems with close orbits and determine astrometric orbit solutions. This will provide key information for the formation and evolution of brown…

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…

Theories that attempt to unify the four fundamental interactions and alternative theories of gravity predict time and/or spatial variation of the fundamental constants of nature. Different versions of these theories predict different…

We performed populations synthesis calculations of single stars and binaries and show that binary evolution is extremely important for Galactic astronomy. We review several binary evolution models and conclude that they give quite different…

With the prevalence of wide-field, time-domain photometric sky surveys, the number of eclipsing white dwarf systems being discovered is increasing dramatically. An efficient method to follow these up will be key to determining any…

Binary systems consisting of a white dwarf and a main-sequence companion with orbital periods up to $\approx 100$ d are often thought to be formed through common envelope evolution which is still poorly understood. To provide new…

Ultracool dwarfs exhibit a remarkably varied set of characteristics which hint at the complex physical processes acting in their atmospheres and interiors. Spectra of these objects not only depend upon their mass and effective temperature,…