“Magnetospheric gate” effect in polars

Abstract

The mass-exchange process in close binary systems which appear as polars is discussed. We point out that the strong magnetic field of the white dwarf in these systems can under certain conditions prevent material from flowing through the L1 point operating as a “magnetospheric gate”. Using some best studied polars as an example we show that the conditions in which the flow through the L1 point is suppressed can be satisfied. A discussion on an alternative mass-exchange mechanism in this situation appears to be quite reasonable.