WIYN Open Cluster Study. LXXVII. Radial-Velocity Measurements and
  Spectroscopic Binary Orbits in the Open Cluster NGC 7789
  We introduce the stellar sample of the WIYN Open Cluster Study
radial-velocity survey for the rich open cluster NGC 7789 (1.6 Gyr, [Fe/H] =
+0.02). This sample lies within an 18$'$ circular radius from the cluster
center (10 pc in projection, or about 2 core radii), and includes giants,
red-clump stars, blue stragglers, red stragglers, sub-subgiants, and
main-sequence stars down to one mag below the turnoff. Our survey began in 2005
and comprises more than 9,000 radial-velocity measurements from the Hydra
Multi-Object Spectrograph on the WIYN 3.5m telescope. We identify 564 likely
cluster members and present the orbital solutions for 83 cluster binary stars
with periods between 1.45$\,$d and 4200$\,$d. From the main-sequence binary
solutions we fit a circularization period of 8.22$^{+3.51}_{-1.35}\,$d. We
calculate an incompleteness-corrected main-sequence binary frequency of 31%
$\pm$ 3% for binaries with periods less than 10$^{4}$ days, similar to other
WOCS open clusters of all ages. We detect a blue straggler binary frequency of
31% $\pm$ 15%, consistent with the similarly aged cluster NGC 6819.
