suhail Masda

The best individual stellar parameters of the close visual binary system “HIP 57894” using the synthetic photometric solution based on Al-Wardat’s complex method are presented. The best match between the synthetic and observed stellar photometry is presented based on the best entire and individual synthetic spectral energy distributions which are constructed by utilizing Atlas9 model atmospheres and two special subroutines of Al-Wardat’s method. From the best synthetic photometric solution, we determine the individual masses and radii as: MA = 1.22 ± 0.18 M⊙, RA = 1.328 ± 0.04 R⊙ and MB = 0.99 ± 0.14 M⊙, RB = 0.975 ± 0.03 R⊙ for the primary and secondary components of the system, respectively. The system depend on the recently published Gaia parallax and the isochrones tracks of the component’s system 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: $T_{\rm eff.}=6220\pm 100$ \,K, $\rm log~g=4.30\pm 0.12$, $R=1.10\pm0.08\,R_\odot$ for the primary component and $T_{\rm eff.}=4870\pm 100$\,K, $\rm log~g=4.60\pm 0.11$, $R=0.709\pm0.07\,R_\odot$ for the secondary component. The recently published dynamical parallax from \textit{Gaia} space mission was used to calculate the total mass of the binary system as $1.75\pm0.06\, \mat...