Statistical Parallax Summary

(1) π from radial velocities, v_r', and the τ component of μ:

π = 4.74 < τ > / < v_r' >.

(2) π from solar motion, v_¤ , and the υ component of μ:

π = 4.74 < υ > / (v_¤ sin λ),

      if the sample is in a small region characterized by a nearly common value of λ
      such as a star field, otherwise,

π = 4.74 < υ sin λ > / (v_¤ < sin²λ >),