Atmospheric and Fundamental Parameters of Eight Nearby Multiple Stars

Abstract

We present the complete set of atmospheric and fundamental parameters, in addition to the masses, for the individual components of eight stellar systems. The list of the systems, whose orbital solutions were published recently, includes seven binaries (HIP 14524, HIP 16025, HIP 46199, HIP 47791, HIP 60444, HIP 61100, HIP 73085) and one triple system (HIP 28671). The systems were analyzed using a spectrophotometric computational technique known as Al-Wardats method for analyzing binary and multiple stellar systems, which makes use of ATLAS9 line-blanketed plane-parallel model atmospheres. Using these estimated parameters, the positions of the components were located on the Hertzsprung–Russell diagram, evolutionary tracks and isochrones to estimate their ages, the range depending on the uncertainties in their metallicities. Five systems were found to be pre-main-sequence stars (HIP 14524, HIP 46199, HIP 60444, HIP 61100, HIP 73085), two were main-sequence stars (the zero-age HIP 28671 and the 6.3 Gyr HIP 16025), and one is a subgiant system (HIP 47791) with an age of 1.4 Gyr. Fragmentation is proposed as the most probable formation process for the eight systems. A comparison between the estimated masses and the dynamical ones lead to new dynamical parallaxes for four systems: (28.63 ± 0.56) mas for HIP 14524, (15.6 ± 0.63) mas for HIP 16025, (9.73 ± 0.26) mas for HIP 47791, and (16.53 ± 0.59) mas for HIP 73085. Hence, the orbital solutions were reclassified. We conclude that Gaia DR3 parallaxes are more precise than those given by Gaia DR2 and Hipparcos 2.