相关论文: Mass ratios of the components in T Tauri binary sy…

Stellar mass is a fundamental parameter that is key to our understanding of stellar formation and evolution, as well as the characterization of nearby exoplanet companions. Historically, stellar masses have been derived from long-term…

We have observed a large sample of spectroscopic binary stars in the Hyades Cluster, using high resolution infrared spectroscopy to detect low mass companions. We combine our double-lined infrared measurements with well constrained orbital…

We report about an ongoing photometric and spectroscopic monitoring survey of about 250 O- and 540 B-type stars in the southern Milky Way with the aim to determine the fraction of close binary systems as a function of mass and to determine…

Binary evolution leads to the formation of important objects crucial to the development of astrophysics, but the statistical properties of binary populations are still poorly understood. The LAMOST-MRS has provided a large sample of stars…

We present a statistical comparison of the mass ratio distribution of companions, as observed in different multiplicity surveys, to the most recent estimate of the single object mass function (Bochanski et al. 2010). The main goal of our…

One of the most effective ways to test stellar evolutionary models is to measure dynamical masses for binary systems at a range of temperatures. In this paper, we present orbits of three young K+M binary systems in Taurus (Hubble~4, FF~Tau,…

Multiple star systems are commonly assumed to form coevally; they thus provide the anchor for most calibrations of stellar evolutionary models. In this paper we study the binary population of the Taurus-Auriga association, using the…

We present low-resolution optical spectra of each component of 10 T Tauri (TT) binary systems with separations ranging from 0.9" to 3.5" and located in the Taurus star-forming region. We derive the spectral type and Halpha equivalent width…

We present first results of a survey for companions among X-ray selected pre-main sequence stars, most of them being weak-line T Tauri stars (WTTS). These T Tauri stars have been identified in the course of optical follow-up observations of…

This paper presents and discusses a critical compilation of accurate, fundamental determinations of stellar masses and radii. We have identified 95 detached binary systems containing 190 stars (94 eclipsing systems, and alpha Centauri) that…

We present a high angular resolution millimeter-wave dust continuum imaging survey of circumstellar material associated with individual components of 23 multiple star systems in the Taurus-Auriga young cluster. Combined with previous…

We present a high spatial resolution, 10-20 micron survey of 65 T Tauri binary stars in Taurus, Ophiuchus, and Corona Australis using the Keck 10 m telescopes. Designed to probe the inner ~1 AU region of the circumstellar disks around the…

Binary properties are usually expressed (for good observational reasons) as a function of primary mass. It has been found that the distribution of companion masses -- the mass ratio distribution -- is different for different primary masses.…

Binary stars and higher-order multiple systems are an ubiquitous outcome of star formation, especially as the system mass increases. The companion mass-ratio distribution is a unique probe into the conditions of the collapsing cloud core…

We present updated results of a high-resolution, magnitude limited (Ks<12 mag) imaging survey of nearby low-mass M6.0-M7.5 field stars. The observations were carried out using adaptive optics at the Gemini North, VLT, Keck II, and Subaru…

O- and B-type stars are often found in binary systems, but the low binary mass-ratio regime is relatively unexplored due to observational difficulties. Binary systems with low mass-ratios may have formed through fragmentation of the…

Various surveys of low-mass binaries in star forming regions have been performed in recent years. They reached opposite conclusions concerning possible binary excesses in some of these associations. I develop a consistent method to…

Close to 100 per cent of massive stars are thought to be in binary systems. The multiplicity of massive stars seems to be intrinsically linked to their formation and evolution, and Massive Young Stellar Objects are key in observing this…

Measurements of masses and ages of young stars from their location in the HR diagram are limited by not only the typical observational uncertainties that apply to field stars, but also by large systematic uncertainties related to…

Multiplicity is ubiquitous among massive stars. While the stellar components usually display similar masses, some binaries with extremely low mass ratios were also observed. Some of them are primordial, while others arise from binary…