A note on axial symmetries
  This note describes a local scheme to characterize and normalize an axial Killing field on a general Riemannian geometry. No global assumptions are necessary, such as that the orbits of the Killing field all have period $2 \pi$. Rather, any Killing field that vanishes at at least one point necessarily has the expected global properties. 
Christopher Beetle and Shawn Wilder
gr-qc