  The radial velocity curves of many spectroscopic binaries (SBs) are perturbed
by gas streams or proximity effects. For SBs with circular orbits, these
perturbations can give rise to spurious orbital eccentricities of high
statistical significance. But tests to identify such anomalous orbits can be
constructed since perturbed velocity curves are in general no longer Keplerian.
The derived tests are applied both to synthetic and to observed velocity
curves.
