  We present results from a radial velocity study of two runaway O-type stars,
HD 14633 (ON8.5 V) and HD 15137 (O9.5 III(n)). We find that HD 14633 is a
single-lined spectroscopic binary with an orbital period of 15.4083 days. The
second target HD 15137 is a radial velocity variable and a possible
single-lined spectroscopic binary with a period close to 1 month. Both binaries
have large eccentricity, small semiamplitude, and a small mass function. We
show the trajectories of the stars in the sky based upon an integration of
motion in the Galactic potential, and we suggest that both stars were ejected
from the vicinity of the open cluster NGC 654 in the Perseus spiral arm. The
binary orbital parameters and runaway velocities are consistent with the idea
that both these stars were ejected by supernova explosions in binaries and that
they host neutron star companions. We find that the time-of-flight since
ejection is longer than the predicted evolutionary timescales for the stars,
which may indicate that they have a lower mass than normally associated with
their spectral classifications and/or that their lives have been extended
through rapid rotation.
