The Araucaria project: High-precision orbital parallaxes and masses of binary stars

Aims. We aim to measure very precise and accurate model-independent masses distances of detached binary stars. Precise at the < 1% level are necessary test calibrate stellar interior evolution models, while independent orbital parallaxes essential check for next Gaia data releases. Methods. combined RV measurements with interferometric observations determine physical parameters ten double-lined spectroscopic systems. report new relative astrometry from VLTI/GRAVITY and, some systems, VLT/UVES spectra radial velocities each component. Results. measured distance systems mass their components a precision as high 0.03% (average 0.2%). They other (effective temperatures, radii, flux ratios, etc.) fit isochrones stage age. also compared our showed that half stars beyond 1 σ parallaxes; although, RUWE is below frequently used cutoff 1.4 reliable astrometry. By fitting telluric features in GRAVITY spectra, we estimated accuracy wavelength calibration be ∼0.02% medium spectral resolution modes. Conclusions. demonstrate combining provides extremely dynamical parallaxes. As they binaries, can benchmark models