The proper motions of OB-associations computed using the old (Hipparcos 1997) and new (van Leeuwen 2007) reductions of the Hipparcos data are in a good agreement with each other. The Galactic rotation curve derived from an analysis of lineof-sight velocities and proper motions of OB-associations is almost flat in the 3kpc neighborhood of the Sun. The angular rotation velocity at the solar distance is Ω 0 = 31 ± 1 km s −1 kpc −1 . The standard deviation of the velocities of OB-associations from the rotation curve is σ = 7.2 km s −1 . The distance scale for OB associations (Blaha & Humphreys 1989) should be shortened by 10-20%. The residual velocities of OB-associations calculated for the new and old reductions differ, on average, by 3.5 km s −1 . The mean residual velocities of OB-associations in the stellar-gas complexes depend only slightly on the data reduction employed.
The kinematics and distribution of classical Cepheids within ∼ 3 kpc from the Sun suggest the existence of the outer ring R1R ′ 2 in the Galaxy. The optimum value of the solar position angle with respect to the major axis of the bar, θ b , providing the best agreement between the distribution of Cepheids and model particles is θ b = 37 ± 13• . The kinematical features obtained for Cepheids with negative Galactocentric radial velocity VR are consistent with the solar location near the descending segment of the outer ring R2. The sharp rise of extinction toward of the Galactic center can be explained by the presence of the outer ring R1 near the Sun.
We use stellar proper motions from the TGAS catalog to study the kinematics of OBassociations. The TGAS proper motions of OB-associations generally agree well with the Hipparcos proper motions. The parameters of the Galactic rotation curve obtained with TGAS and Hipparcos proper motions agree within the errors. The average onedimensional velocity dispersion inside 18 OB-associations with more than 10 TGAS stars is σ v = 3.9 km s −1 , which is considerably smaller, by a factor of 0.4, than the velocity dispersions derived from Hipparcos data. The effective contribution from orbital motions of binary OB-stars into the velocity dispersion σ v inside OB-associations is σ b = 1.2 km s −1 . The median virial and stellar masses of OB-associations are equal to 7.1 10 5 and 9.0 10 3 M ⊙ , respectively. Thus OB-associations must be unbound objects provided they do not include a lot of dense gas. The median star-formation efficiency is ǫ = 2.1 percent. Nearly one third of stars of OB-associations must lie outside their tidal radius. We found that the Per OB1 and Car OB1 associations are expanding with the expansion started in a small region of 11-27 pc 7-10 Myr ago. The average expansion velocity is 6.3 km s −1 .
The kinematical features of the Sagittarius (R = 5.7 kpc), Carina (R = 6.5 kpc), Cygnus (R = 6.8 kpc), and Perseus (R = 8.2 kpc) arm fragments suggest the existence of two spiral patterns rotating at different angular velocities in the Galaxy. The inner spiral pattern represented by the Sagittarius arm rotates at the angular velocity of the bar, Ω b = 60 ± 5 km s −1 kpc −1 . The outer spiral pattern, which consists of the Carina, Cygnus and Perseus arms, rotates at a smaller angular velocity, Ω s = 12-22 km s −1 kpc −1 . The existence of the outer slow tightly wound spiral pattern and the inner fast spiral pattern can be explained in terms of the results of numerical simulations of the dynamics of the outer pseudoring. The OLR of the bar must be located between the Sagittarius and Carina arms. The Cygnus arm appears as a connecting link between the fast and slow spiral patterns.
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