Related papers: Absolute Magnitude Calibration for W UMa-Type Syst…
In this study we investigate the calibration of surface brightness--color (SBC) relations based solely on eclipsing binary stars. We selected a sample of 35 detached eclipsing binaries with trigonometric parallaxes from Gaia DR1 or…
We have calibrated the Tip of the Red Giant Branch (TRGB) using our recent catalog of homogeneous, high-accuracy Globular Cluster (GC) distances. The GC distances were determined by a global joint fit to optical period-Wesenheit relations…
We present multi-epoch spectroscopic observations of the massive binary system WR21a, which include the January 2011 periastron passage. Our spectra reveal multiple SB2 lines and facilitate an accurate determination of the orbit and the…
In preparation for the release of the astrometric orbits of Gaia, Shahaf et al. (2019) proposed a triage technique to identify astrometric binaries with compact companions based on their astrometric semi-major axis, parallax, and primary…
Parallaxes for 331 classical Cepheids, 31 Type II Cepheids and 364 RR Lyrae stars in common between Gaia and the Hipparcos and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution…
Gaia will obtain astrometry and spectrophotometry for essentially all sources in the sky down to a broad band magnitude limit of G=20, an expected yield of 10^9 stars. Its main scientific objective is to reveal the formation and evolution…
We present results of the analysis of 70 RR Lyrae stars located in the bar of the Large Magellanic Cloud (LMC). Combining spectroscopically determined metallicity of these stars from the literature with precise periods from the OGLE III…
Using parallaxes from Gaia Early Data Release 3 (EDR3), we determine multi-wavelength BVI, JHK, and [3.6] & [4.5] micron absolute magnitudes for 37 nearby Milky Way Cepheids, covering the period range between 5 and 60 days. We apply these…
Establishing the period--Wesenheit relation requires independent and accurate distance measurements of classical Cepheids (DCEPs). The precise distance provided by an associated open cluster independently calibrates the period--Wesenheit…
Gaia Data Release 2 (Gaia DR2) contains results for 1693 million sources in the magnitude range 3 to 21 based on observations collected by the European Space Agency Gaia satellite during the first 22 months of its operational phase. We…
We report the detection of a very low mass star (VLMS) companion to the primary star 1SWASPJ234318.41+295556.5A (J2343+29A), using radial velocity (RV) measurements from the PARAS (PRL Advanced Radial-velocity Abu-sky Search) high…
Pair-instability supernovae leave behind no compact remnants, resulting in a predicted gap in the distribution of stellar black-hole masses. Gravitational waves from binary black-hole mergers probe the relevant mass range and analyses of…
We investigate in detail the LiTE of the most probable binary candidate TU UMa. We used a new code applied on previously available and newly determined maxima timings to confirm binarity and refine parameters of the orbit of the RRab…
Phenomenological characteristics of the sample of the Algol-type stars are revised using a recently developed NAV ("New Algol Variable") algorithm (2012Ap.....55..536A, 2012arXiv 1212.6707A) and compared to that obtained using common…
We examine the capacity to identify binary systems from astrometric deviations alone. We apply our analysis to the Gaia eDR3 and DR2 data, specifically the Gaia Catalogue of Nearby Stars. We show we must renormalize (R)UWE over the local…
We present single-epoch black-hole mass (\mbh) estimators based on the rest-frame ultraviolet (UV) \MgII\ 2798\AA\ and optical \Hb\ 4861\AA\ emission lines. To enlarge the luminosity range of active galactic nuclei (AGNs), we combine the 31…
Based on SDSS and South Galactic Cap of u-band Sky Survey (SCUSS) early data, we use star counts method to estimate the Galactic structure parameters in an intermediate latitude with 10,180 main-sequence (MS) stars in absolute magnitude…
The period, mass ratio, eccentricity, and other orbital parameters are fundamental for investigating binary star evolution. However, the number of binaries with known orbital parameters remains limited. Utilizing the LAMOST-MRS survey, we…
Wide binary stars are important for testing alternative models of gravitation in the weak-field regime and understanding the statistical outcomes of dynamical interactions in the general Galactic field. The Gaia mission's collection of…
We use 1837 DA white dwarfs with high signal to noise ratio spectra and Gaia parallaxes to verify the absolute calibration and extinction coefficients for the Galaxy Evolution Explorer (GALEX). We use white dwarfs within 100 pc to verify…