The precise determination of the physical and dynamical parameters of the HIP 109951 triple star system (WDS J22161-0705AB) which is formed by the A, Ba, and Bb components are presented. The binary nature of component B was recently confirmed by studying the radial velocities. The analysis of the system follows Al-Wardat's complex method for analyzing CVBS which employs Kurucz (Atlas9) line blanketed plane-parallel atmospheres simultaneously with an analytic method for dynamical analysis (we used Docobo's method) to calculate the parameters of this triple system. The result of our study yielded the following parameters: T A eff = 5836 ± 80 K, R A = 1.090 ± 0.039R , logg A = 4.45 ± 0.06, M A = 1.05 ± 0.16M ; T Ba eff = 5115 ± 80 K, R Ba = 0.596 ± 0.05R , log g Ba = 4.60 ± 0.07, M Ba = 0.83 ± 0.16M , T Bb eff = 4500 ± 80 K, R Bb = 0.490 ± 0.06R , log g Bb = 4.65 ± 0.07, and M Bb = 0.67 ± 0.16M based on the revised Hipparcos parallax. The orbital solution gave a total mass as M = 2.59M based on Gaia parallax and M = 2.15M based on the revised Hipparcos parallax. The synthetic spectral energy distributions (SED) and synthetic stellar photometry of the entire system and individual components are given and compared with the available observational ones. Finally, the positions of the system components on the HR diagram and the evolutionary tracks are given and their formation and the evolution of the system are discussed.

The perfect physical and geometrical parameters of the main-sequence close visual binary system (CVBS); HIP 105947, are explicitly presented. These parameters have been constructed conclusively using Al-Wardat's complex method for analysing CVBSs, which is a method for constructing a synthetic spectral energy distribution (SED) for the entire binary system using individual SED for each component star. Which in its turn built using Kurucz (ATLAS9) line-blanketed plane-parallel models. At the same time, the orbital parameters for the system are calculated using Tokovinin's dynamical method for constructing the best orbits of interferometric binary system. Henceforth, the mass-sum of the components, the △θ and △ρ residuals for the system are introduced. The combination of Al-Wardat's and Tokovinin's methods yields the estimation of the physical and geometrical parameters to their best values. The positions of the components of the system on the evolutionary tracks and isochrones are plotted and their formation and evolution are discussed.

We present the complete set of physical and geometrical parameters of the visual close binary system GJ 9830 for the first time by using Al-Wardat's complex method. This method combines magnitude difference from speckle interferometry, synthetic spectral energy distributions of the binary components which are constructed depending on grids of Kurucz blanketed models (Atlas9), along with the orbital solution by using Tokovinin's dynamical method to estimate the parameters of the individual components. The analysis of the system by using synthetic photometry resulted in the following set of parameters: T eff. = 6220 ± 100 K, log g = 4.30 ± 0.12, R = 1.10 ± 0.08 R for the primary component and T eff. = 4870±100 K, log g = 4.60±0.11, R = 0.709±0.07 R for the secondary component. The recently published dynamical parallax from Gaia space mission was used to calculate the total mass of the binary system as 1.75±0.06 M which coincides with those estimated by using Al-Wardat's method as M A = 1.18 ± 0.10 M , M B = 0.75 ± 0.08 M . The analysis of the system reveals that both components belong to main sequence stars with an age around 1.4 ± 0.50 Gyr. The evolutionary tracks and isochrones of the system's components are discussed, and the fragmentation process is suggested as the most likely process for the formation of the system.

We present the stellar parameters of the individual components of the two old close binary systems HIP 14075 and HIP 14230 using synthetic photometric analysis. These parameters are accurately calculated based on the best match between the synthetic photometric results within three different photometric systems with the observed photometry of the entire system. From the synthetic photometry, we derive the masses and radii of HIP 14075 as: M A = 0.99 ± 0.19 M , R A = 0.877 ± 0.08 R for the primary and M B = 0.96 ± 0.15 M , R B = 0.821 ± 0.07 R for the secondary, and of HIP 14230 as: M A = 1.18 ± 0.22 M , R A = 1.234 ± 0.05 R for the primary and M B = 0.84 ± 0.12 M , R B = 0.820 ± 0.05 R for the secondary, both systems depend on Gaia parallaxes. Based on the positions of the components of the two systems on a theoretical Hertzsprung-Russell diagram, we find that the age of HIP 14075 is 11.5 ± 2.0 Gyr and of HIP 14230 is 3.5 ± 1.5 Gyr. Our analysis reveals that both systems are old close binary systems (≈> 4 Gyr). Finally, the positions of the components of both systems on the stellar evolutionary tracks and isochrones are discussed.

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