Related papers: Orbits and Dynamical Masses for the Active Hyades …

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…

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…

We present the results of a proper motion survey of the Hyades to search for brown dwarfs, based on UKIDSS and 2MASS data. This survey covers ~275 square degrees to depth of K~15 mag, equivalent to a mass of 0.05 solar masses assuming a…

The existence of a kinematically defined moving group of stars centred at U = -40, V = -17 km/s referred to as the Hyades Supercluster, has been suggested as the debris of an originally large star forming event, with its core being the…

In this paper, we present the analysis of the stellar system HIP 101227 to determine the actual number of components in the system, and their properties. We use dynamical modeling and complex spectrophotometric (involving atmospheric…

In this paper, we present our HARPS radial-velocity data for eight low-activity solar-type stars belonging to the HARPS volume-limited sample: HD6718, HD8535, HD28254, HD290327, HD43197, HD44219, HD148156, and HD156411. Keplerian fits to…

Main aim of this paper is the first detailed analysis of multiple system V2083 Cyg and to reveal its basic physical properties. The system was studied by method of the light and radial velocity curves analysis, together with the…

We report the discovery of a nearby star with a very large proper motion of 5.06 +/- 0.03 arcsec/yr. The star is called SO025300.5+165258 and referred to herein as HPMS (high proper motion star). The discovery came as a result of a search…

We present optical and near-infrared adaptive optics (AO) imaging and spectroscopy of 13 ultracool (>M6) companions to late-type stars (K7-M4.5), most of which have recently been identified as candidate members of nearby young moving groups…

Combing Gaia DR2 with LAMOST DR5, we spectroscopically identified 924 hot subdwarf stars, among which 32 stars exhibit strong double-lined composite spectra. We measured the effective temperature $T_{\rm eff}$, surface gravity $\log\,g$,…

We compare the accurate empirical mass-luminosity (M-L) relation based on five Hyades binary systems to predictions of stellar models calculated with various input parameters (helium, metallicity, age) or physics (mixing-length ratio, model…

We present an independent Doppler validation and dynamical orbital analysis of the two-planet system HD 107148, which was recently announced in Rosenthal et al. (2021). Our detailed analyses are based on literature HIRES data and newly…

A set of 41 nearby stars (closer than 25 pc) is investigated which have very wide binary and common proper motion (CPM) companions at projected separations between 1000 and $200 000$ AU. These companions are identified by astrometric…

We present an astrometric analysis of the binary systems ABDorA /ABDorC and ABDorBa / ABDorBb. These two systems of well-known late-type stars are gravitationally associated and they constitute the quadruple ABDoradus system. From the…

Joint analysis of radial velocities and position measurements of five hierarchical stellar systems is undertaken to determine elements of their inner and outer orbits and, whenever possible, their mutual inclinations. The inner and outer…

The number of multi-planet systems known to be orbiting their host stars with orbital periods that place them in mean motion resonances is growing. For the most part, these systems are in first-order resonances and dynamical studies have…

This is the fifth paper in a series aimed at studying the chromospheres of active binary systems using several optical spectroscopic indicators to obtain or improve orbital solution and fundamental stellar parameters. We present here the…

We report on the discovery of a fourth component in the HD 221356 star system, previously known to be formed by an F8V, slightly metal-poor primary ([Fe/H]=-0.26), and a distant M8V+L3V pair. In our ongoing common proper motion search based…

We combine new high resolution imaging and spectroscopy from Keck/NIRC2, Discovery Channel Telescope/DSSI, and Keck/HIRES with published astrometry and radial velocities to measure individual masses and orbital elements of the GJ 3305 AB…

Analyses of multi-epoch, high-resolution (R ~ 50.000) optical spectra of the O-type star HD 152246 (O9 IV according to the most recent classification), complemented by a limited number of earlier published radial velocities, led to the…