Spectropolarimetric orbits of symbiotic stars: SY Muscae.

We present a formalism describing the change in position angle with orbital motion of Raman-scattered lines in symbiotic binaries. Straightforward inversion techniques allow this formalism to be used in the determination of `polarimetric orbits'. The orbital quantities which can be estimated from suitable data are the period P; the eccentricity, e; the inclination, i; the longitude of periastron, ω; and the position angle of the line of nodes, {OMEGA}. We illustrate the method with an analysis of data for SY Mus.