Extending Stellar Astrophysics to Planetary Masses
Trent Dupuy
Gemini Observatory

The motion of objects contains more information than emitted light alone, and astrometry has long been a powerful tool for determining some of the most fundamental astrophysical properties, like mass. I will present an empirical view of substellar evolution from unique high-precision infrared astrometry programs. A large sample of parallaxes has allowed me to map the changes in absolute flux from the end of the stellar main sequence to the coldest known brown dwarfs. By measuring brown dwarf binary orbits I have determined fundamental parameters, most notably masses, enabling the most stringent tests of theoretical models. I will conclude by discussing the future landscape of dynamical mass work, including spectroscopic follow-up opportunities with Keck and HST and an extension of the observed sample to planetary masses. In the next decade, new facilities like Gaia, LSST, and TMT will greatly expand our ability to measure dynamical masses beyond the finite sample of solar neighborhood ultracool binaries to wide-ranging objects of well-determined ages and metallicities.