Masses of the components of SB2 binaries observed with Gaia. II. Masses derived from PIONIER interferometric observations for Gaia validation

TL;DR

This study combines interferometric and spectroscopic data to accurately determine stellar masses in SB2 binaries, validating Gaia's mass measurements and refining stellar models.

Contribution

It provides the first interferometric mass measurements for SB2 binaries observed with Gaia, enhancing the validation of Gaia's astrometric mass determinations.

Findings

Derived stellar masses are a few percent larger than standard models.

Confirmed Hipparcos parallaxes for the three binaries.

Achieved mass measurement accuracy within 1% when combined with Gaia data.

Abstract

In anticipation of the Gaia astrometric mission, a sample of spectroscopic binaries is being observed since 2010 with the Sophie spectrograph at the Haute--Provence Observatory. Our aim is to derive the orbital elements of double-lined spectroscopic binaries (SB2s) with an accuracy sufficient to finally obtain the masses of the components with relative errors as small as 1 % when combined with Gaia astrometric measurements. In order to validate the masses derived from Gaia, interferometric observations are obtained for three SB2s in our sample with F-K components: HIP 14157, HIP 20601 and HIP 117186. The masses of the six stellar components are derived. Due to its edge-on orientation, HIP 14157 is probably an eclipsing binary. We note that almost all the derived masses are a few percent larger than the expectations from the standard spectral-type-mass calibration and mass-luminosity relation. Our calculation also leads to accurate parallaxes for the three binaries, and the Hipparcos parallaxes are confirmed.