Evidence of the Galactic outer ring R1R2' from young open clusters and   OB-associations
  The distribution of young open clusters in the Galactic plane within 3 kpc from the Sun suggests the existence of the outer ring R1R2' in the Galaxy. The optimum value of the solar position angle with respect to the major axis of the bar, theta_b, providing the best agreement between the distribution of open clusters and model particles is theta_b=35 +/- 10 degrees. The kinematical features obtained for young open clusters and OB-associations with negative Galactocentric radial velocity VR indicate the solar location near the descending segment of the outer ring R2. 
A. M. Melnik, P. Rautiainen, E. V. Glushkova, A. K. Dambis
astro-ph.GA