Related papers: Absolute Magnitude Calibration for the W UMa-type …
Tycho-Gaia Astrometric Solution (TGAS) parallax data are used to determine absolute magnitudes $M_V$ for 318 W~UMa-type (EW) contact binary stars. A very steep (slope $\simeq -9$), single-parameter ($\log{P}$), linear calibration can be…
A modification to the absolute magnitude calibration for W~UMa-type systems, taking into account differences in metal abundances, is derived on the basis of contact binary systems recently discovered in metal-poor clusters. A preliminary…
Parallaxes of W UMa stars in the Hipparcos catalogue have been analyzed. 31 W UMa stars, which have the most accurate parallaxes ($\sigma_{\pi}/\pi<0.15$) which are neither associated with a photometric tertiary nor with evidence of a…
The accuracy of absolute parameters' estimation in contact binary systems is important for investigating their evolution and solving some challenges. The Gaia DR3 parallax is one of the methods used for estimating the absolute parameters,…
Lutz-Kelker bias corrected absolute magnitude calibrations for the detached binary systems with main-sequence components are presented. The absolute magnitudes of the calibrator stars were derived at intrinsic colours of Johnson-Cousins and…
We present an M_V absolute magnitude calibration including the B-V colour and [Fe/H] metallicity for the red clump stars in the globular and open clusters with a wide range of metallicities: M_V =…
A new calibration of the Mv-W(OI 7774) relationship has been calculated using better estimates of reddenings and distances to a sample of 27 calibrator stars of A-G spectral types, based on accurate parallaxes and proper motions from the…
The present determination of the absolute magnitude $M_V(RR)$ of RR Lyrae stars is twofold, relying upon Hipparcos proper motions and trigonometric parallaxes separately. First, applying the statistical parallax method to the proper…
The luminosity function for contact binary stars of the W~UMa-type is evaluated on the basis of the ASAS photometric project covering all stars south of delta= +28 within a magnitude range 8<V<13. Lack of colour indices enforced a…
The ESA HIPPARCOS satellite has provided astrometry of unprecedented accuracy, allowing to reassess, improve and refine the pre-HIPPARCOS luminosity calibrations. We review the "classical" absolute magnitude calibrations with the…
We used the updated [Fe/H] abundances of 168 F-G type dwarfs and calibrated them to a third order polynomial in terms of reduced ultraviolet excess, $\delta_{0.41}$ defined with $ugr$ data in the SDSS. We estimated the $M_g$ absolute…
Possible M-type contact binaries were investigated by selecting W UMa-type variables with orbital periods below the 0.22-day cutoff. Gaia parallaxes were combined with Gaia and 2MASS photometry to obtain G and J-band absolute magnitudes of…
We present a new procedure for photometric parallax estimation. The data for 1236 stars provide calibrations between the absolute magnitude offset from the Hyades main-sequence and the UV-excess for different (B-V)o colour-index intervals,…
W Ursa Majoris (W UMa)-type contact binary systems (CBs) are useful statistical distance indicators because of their large numbers. Here, we establish (orbital) period-luminosity relations (PLRs) in 12 optical-to-mid-infrared bands (GBV…
In this study, photometric metallicity and absolute magnitude calibrations were derived using F-G spectral type main-sequence stars in the Solar neighbourhood with precise spectroscopic, photometric and Gaia astrometric data for UBV…
Reviewing the empirical and theoretical parameter relationships between various parameters is a good way to understand more about contact binary systems. In this investigation, two-dimensional (2D) relationships for P-M_V(system), P-L_1,2,…
New relationships between the orbital period and some parameters of W Ursae Majoris (W UMa) type systems are presented in this study. To investigate the relationships, we calculated the absolute parameters of a sample of 118 systems. For…
I review statistical parallax absolute magnitude determinations which employ data from the HIPPARCOS satellite for RR Lyrae and Cepheid variables, and for several other stellar classes. Five groups have studied the RR Lyrae stars, and the…
Hipparcos photometric data for the massive O-type binary UW CMa were analysed within the framework of the Roche model. Photometric solutions were obtained for five mass ratios in the $q=M_2/M_1=0.5-1.5$ range. The system is found to be in a…
The application of the Stromgren photometric luminosity calibrations to different types of CP stars is reexamined in the light of the new Hipparcos data. A first attempt is made to use the LM statistical parallax method (Luri et al., 1996)…