Determination of the Galactic Rotation Curve from OB Stars
  We consider three samples of O- and B-type stars from the solar neighborhood
0.6--4 kpc for which we have taken the distances, line-of-sight velocities, and
proper motions from published sources. The first sample contains 120 massive
spectroscopic binaries. O stars with spectroscopic distances from Patriarchi et
al. constitute the second sample. The third sample consists of 168 OB3 stars
whose distances have been determined from interstellar calcium lines. The
angular velocity of Galactic rotation at the solar distance $\Omega_0,$ its two
derivatives $\Omega'_0$ and $\Omega"_0,$ and the peculiar velocity components
of the Sun $(U,V,W)_\odot$ are shown to be well determined from all three
samples of stars. They are determined with the smallest errors from the sample
of spectroscopic binary stars and the sample of stars with the calcium distance
scale. The fine structure of the velocity field associated with the influence
of the Galactic spiral density wave clearly manifests itself in the radial
velocities of spectroscopic binary stars and in the sample of stars with the
calcium distance scale.
