Orbital Motion in Pre-Main Sequence Binaries

TL;DR

This study maps the orbital motion of pre-main sequence binary stars in Taurus using adaptive optics, providing preliminary orbits and insights into their orbital characteristics to aid in mass measurements.

Contribution

The paper presents new orbital measurements and preliminary orbit solutions for several pre-main sequence binaries, expanding understanding of their orbital dynamics.

Findings

Preliminary orbits for four binaries are presented.

Seven binaries show curvature in their relative motion.

Some binaries exhibit linear motion, indicating potential bound systems.

Abstract

We present results from our ongoing program to map the visual orbits of pre-main sequence binaries in the Taurus star forming region using adaptive optics imaging at the Keck Observatory. We combine our results with measurements reported in the literature to analyze the orbital motion for each binary. We present preliminary orbits for DF Tau, T Tau S, ZZ Tau, and the Pleiades binary HBC 351. Seven additional binaries show curvature in their relative motion. Currently, we can place lower limits on the orbital periods for these systems; full solutions will be possible with more orbital coverage. Five other binaries show motion that is indistinguishable from linear motion. We suspect that these systems are bound and might show curvature with additional measurements in the future. The observations reported herein lay critical groundwork toward the goal of measuring precise masses for low-mass pre-main sequence stars.