  We present multi-epoch spectroscopy of "heartbeat stars," eccentric binaries
with dynamic tidal distortions and tidally induced pulsations originally
discovered with the Kepler satellite. Optical spectra of six known heartbeat
stars using the Wyoming Infrared Observatory 2.3 m telescope allow measurement
of stellar effective temperatures and radial velocities from which we determine
orbital parameters including the periods, eccentricities, approximate mass
ratios, and component masses. These spectroscopic solutions confirm that the
stars are members of eccentric binary systems with eccentricities e>0.34 and
periods P=7-20 days, strengthening conclusions from prior works which utilized
purely photometric methods. Heartbeat stars in this sample have A- or F-type
primary components. Constraints on orbital inclinations indicate that four of
the six systems have minimum mass ratios q=0.3-0.5, implying that most
secondaries are probable M dwarfs or earlier. One system is an eclipsing,
double-lined spectroscopic binary with roughly equal-mass mid-A components
(q=0.95), while another shows double-lined behavior only near periastron,
indicating that the F0V primary has a G1V secondary (q=0.65). This work
constitutes the first measurements of the masses of secondaries in a
statistical sample of heartbeat stars. The good agreement between our
spectroscopic orbital elements and those derived using a photometric model
support the idea that photometric data are sufficient to derive reliable
orbital parameters for heartbeat stars.
