Abstract

Dynamical masses of substellar companions are critical tools to validate models of planet and brown dwarf cooling, test their input physics, and improve our understanding of the formation and evolution of these objects. However, only about 15 dynamical masses of substellar companions with well-constrained luminosities and ages have been measured, most of which are old (>1 Gyr). In this talk, I will detail our measurement of the young brown dwarf companion HD 984 B’s dynamical mass by combining Hipparcos-Gaia astrometry, high-contrast imaging, and radial velocities. HD 984 B is particularly interesting, as its young age (30-200 Myr) and high luminosity near the substellar boundary enable models to be tested in a previously unexplored regime. I will then discuss a new direct imaging survey that uses astrometric accelerations as dynamical signposts for undiscovered, wide-separation planets and brown dwarfs. The goal of this program is to dramatically improve planet yields over previous imaging campaigns that lacked informed target selection.