  Depending principally on mass, the compact object remnant left behind after a
star's life may be a white dwarf (WD), neutron star (NS), or black hole (BH).
While we have large samples of each of these remnants, we lack knowledge of the
exact conditions separating these outcomes. The boundary between low-mass BHs
and massive NSs is particularly poorly understood, as few objects between 2-5
$M_\odot$ are known. To probe this regime, we search the APOGEE DR17 dataset of
657,000 unique stars for binary systems with one stellar component that exhibit
large radial velocity shifts over multiple observations. We identify 4751
likely binary systems, and estimate a minimum mass for each system's "invisible
companion" under the assumption of tidal synchronization. Two systems have
companion masses $\gtrsim$ 2 $M_\odot$, although we conclude that neither are
good candidates for possessing a mass-gap NS or BH companions.
