Trigonometric Parallaxes of Massive Star Forming Regions: I. S 252 &   G232.6+1.0
  We are conducting a large program with the NRAO Very Long Baseline Array (VLBA) to measure trigonometric parallaxes of massive star-forming regions across the Milky Way. Here we report measurement of the parallax and proper motion of methanol masers in S 252 and G232.6+1.0. The parallax of S 252 is 0.476 +/- 0.006 mas (2.10 [+0.027/-0.026] kpc), placing it in the Perseus spiral arm. The parallax of G232.6+1.0 is 0.596 +/- 0.035 mas (1.68 [+0.11/-0.09] kpc), placing it between the Carina-Sagittarius and Perseus arms, possibly in a Local (Orion) spur of the Carina-Sagittarius arm. For both sources, kinematic distances are significantly greater than their parallax distances. Our parallaxes and proper motions yield full space motions accurate to about 1 km/s. Both sources orbit the Galaxy about 13 km/s slower than circular rotation. 
M. J. Reid, K. M. Menten, A. Brunthaler, X. W. Zheng, L. Moscadelli   and Y. Xu