Dynamical Masses for Pre-Main Sequence Stars: A Preliminary Physical Orbit for V773 Tau A

TL;DR

This study presents preliminary orbital and mass measurements for the V773 Tau A binary, a pre-main sequence system, using interferometric and radial-velocity data, enabling comparison with stellar evolution models.

Contribution

It provides the first preliminary physical orbit and dynamical mass estimates for V773 Tau A, a pre-main sequence binary, and compares these with stellar models.

Findings

Component masses: 1.54 and 1.332 solar masses.

Orbit inclination: 66 degrees.

Model predictions agree within 2-sigma with dynamical masses.

Abstract

We report on interferometric and radial-velocity observations of the double-lined 51-d period binary (A) component of the quadruple pre-main sequence (PMS) system V773 Tau. With these observations we have estimated preliminary visual and physical orbits of the V773 Tau A subsystem. Among other parameters, our orbit model includes an inclination of 66.0 $\pm$ 2.4 deg, and allows us to infer the component dynamical masses and system distance. In particular we find component masses of 1.54 $\pm$ 0.14 and 1.332 $\pm$ 0.097 M$_{\sun}$ for the Aa (primary) and Ab (secondary) components respectively. Our modeling of the subsystem component spectral energy distributions finds temperatures and luminosities consistent with previous studies, and coupled with the component mass estimates allows for comparison with PMS stellar models in the intermediate-mass range. We compare V773 Tau A component properties with several popular solar-composition models for intermediate-mass PMS stars. All models predict masses consistent to within 2-sigma of the dynamically determined values, though some models predict values that are more consistent than others.