THE BARR EFFECT - A STATISTICAL STUDY

The reality of the 'Barr effect' is established by using nonparametric statistical tests on the DAO Eighth Catalogue sample. For orbits of r easonable quality, it is present only for orbital periods less than or similar to 3 days, with a preferred direction for longitudes of peria stron of omega congruent-to 100-degrees. These characteristics are qua litatively consistent with measured radial velocities being biassed by gas streams. The Barr effect is not detectable in Griffin's 'Spectros copic Binary Orbits' series.