  This paper computes co-rotating and contra-rotating impact-parameter formulas
in the plane of symmetry for any plane symmetric and axisymmetric rotating body
in all metric theories of gravity, including general relativity.
Impact-parameter formulas are useful to compute the appearance of accreting
black holes, neutron stars, and other emitting or reflecting matter near a
gravitationally compact rotating body. These rotating-body impact-parameter
formulas generalize similar impact-parameter formulas for the Kerr case derived
by Bardeen and coworkers in 1972, and another general-metric formula for the
spherical case published by Bodenner and Will in 2003.
