A Study of Eight Visual-spectroscopic Southern Binaries Using Recent SOAR Observations

Abstract

Speckle observations performed between 2019 and 2022 with the HRCam attached to the 4.1 m SOAR telescope (Cerro Pachón, Chile) permitted to improve visual orbits of the southern binaries WDS 01243-0655 (BU 1163), WDS 09275-5806 (CHR 240), WDS 12114-1647 (S 643 AaAb), WDS 13317-0219 (HDS 1895), WDS 15282-0921 (BAG 25 AaAb), WDS 17304-0104 (STF 2173), WDS 19598-0957 (HO 276), and WDS 21274-0701 (HDS 3053). All of them are spectroscopic binaries, of which six are SB2, so relevant information about their individual masses has been obtained. Moreover, comparison between different values of their parallaxes (orbital, dynamic, and ANAPAR, a color-dependent model suitable for binary systems attending to the exact locations of the components on the MS in the HR diagram) with those provided by Hipparcos and Gaia missions, along with comments for each binary are presented. The luminosity determination of the 16 components allowed us to estimate their approximate age and position on the HR diagram as well.

Keywords

• Orbit determination
• Orbits
• Stellar astronomy
• Stellar dynamics
• Stellar evolutionary tracks
• Stellar masses