Related papers: Absolute Magnitude Calibration for the W UMa-type …
We present an absolute magnitude calibration for red giants with the colour magnitude diagrams of six Galactic clusters with different metallicities i.e. M92, M13, M3, M71, NGC 6791 and NGC 2158. The combination of the absolute magnitudes…
This paper presents the results of a combined spectroscopic and photometric study of 20 contact binary systems: HV Aqr, OO Aql, FI Boo, TX Cnc, OT Cnc, EE Cet, RWCom, KR Com, V401 Cyg, V345 Gem, AK Her, V502 Oph, V566 Oph, V2612 Oph, V1363…
We present a new calibration method based on cross-correlations with WMAP and apply it to data from the Atacama Cosmology Telescope (ACT). ACT's observing strategy and map making procedure allows an unbiased reconstruction of the modes in…
We have used main-sequence fitting to calibrate the distances to the globular clusters NGC 6397, M5, NGC 288, M71 and 47 Tucanae, matching the cluster photometry against data for subdwarfs with precise Hipparcos parallax measurements and…
Modern spectroscopic surveys combined with Gaia distances are enabling reliable estimates of fundamental parameters for hundreds of Galactic O-type stars and the full range of spectral types and luminosity classes. Here we provide updated,…
Color Magnitude Diagrams (CMDs) of individual stars in 8 Globular Clusters in M31 down to about 1 mag fainter (V$\sim 26.5$) than the Horizontal Branch have been obtained with the Hubble Space Telescope. In particular, we observed G280 and…
The absolute visual magnitude as function of the observed colour (B-V), also named Hertzsprung-Russell diagram can be described through five equations; that in presence of calibrated stars means eight constants. The developed framework…
The recently discovered eclipsing binary system TYC 2675-663-1 is a X-ray source, and shows properties in the optical that are similar to the W UMa systems, but are somewhat unusual compared to what is seen in other contact binary systems.…
By analyzing two sets of complete $BVR_cI_c$ light curves of V342 UMa and three sets of complete $BVR_cI_c$ light curves of V509 Cam, we determined that the two systems are both W-subtype contact binaries and that V342 UMa shows a shallow…
HIPPARCOS astrometric and kinematical data of oxygen-rich Mira variables are used to calibrate absolute near-infrared magnitudes and kinematic parameters. Two sets of near-infrared magnitudes compiled from different authors are used:…
We propose a zero-point photometric calibration of the data from the ACS/WFC on board the Hubble Space Telescope, based on a spectrum of Vega and the most up to date in-flight transmission curves of the camera. This calibration is accurate…
We present the strategies adopted in the relative and absolute calibration of two different data sets: U,B,V,I-band images collected with the Wide Field Imager (WFI) mosaic camera mounted on the 2.2m ESO/MPI Telescope and u,v,b,y Stroemgren…
In this paper we investigate whether a misestimate of proper motions could have been a source of substantial systematic errors in the statistical parallax determination of the absolute magnitude of RR Lyrae stars. In an earlier paper, we…
We evaluated new colour-transformations for the Sloan photometry by 224 standards and used them to revise both the equations for photometric parallax estimation and metallicity calibration cited by Karaali et al. (2003). This process…
We present a new calibration of the seven-color Vilnius system in terms of [Fe/H], applicable to F-M stars in the metallicity range -2.8<[Fe/H]<+0.5. We employ a purely empirical approach, based on ~1000 calibrating stars with…
In this paper, we estimated the physical and geometrical characteristics of the visually close binary stellar system Hip 45571, using Al-Wardat's method for analyzing binary and multiple stellar systems. We estimated the physical properties…
Accurate parallaxes from Gaia DR1 (TGAS) are combined with GALEX visual Nuv magnitudes to produce absolute Mnuv magnitudes and an ultraviolet HR diagram for a large sample of astrometric stars. A functional fit is derived of the lower…
We present new parallax measurements of 7 long-period (> 10 days) Milky Way Cepheids (SS CMa, XY Car, VY Car, VX Per, WZ Sgr, X Pup and S Vul) using astrometry from spatial scanning of WFC3 on HST. Observations were obtained at 6 month…
A survey of 30 nearby M6.0-M7.5 dwarfs with Ks<12 mag utilizing the Hokupa'a adaptive optics system at the Gemini North Telescope has discovered 3 new binary systems. All 3 systems have separations between 0.12-0.29 arcsec (3-10 AU) with…
The $B$ $V$ $R_c$ $I_c$ bands light curves of the newly discovered binary system \astrobj{GSC 03122-02426} are obtained and analyzed using the Wilson-Devinney (W-D) code. The solutions suggest that the mass ratio of the binary system is $q…