  The majority of stars have one or more stellar companions. As exoplanets
continue to be discovered, it is crucial to examine planetary systems to
identify their stellar companions. By observing a change in proper motion,
companions can be detected by the acceleration they induce on their host stars.
We selected 701 stars from the Hipparcos-Gaia Catalog of Accelerations (HGCA)
that have existing adaptive optics imaging data gathered with Gemini/NIRI. Of
these, we examined 21 stars known to host planet candidates and reduced their
archival NIRI data with Gemini's DRAGONS software. We assessed these systems
for companions using the NIRI images as well as Renormalized Unit Weight Error
values in Gaia and accelerations in the HGCA. We detected three known visible
companions and found two more systems with no visible companions but
astrometric measurements indicating likely unresolved companions.
