Accretion in High Magnetic Fields: The Stellar Interaction

Continuing the theme of the previous two papers, the link between the stellar components of a highly-magnetic CV is considered with emphasis on the current strongest-field example, ar. Progress toward a detailed understanding of this binary includes an accurate orbital ephemeris and the derivation of a system geometry that implies two accretion streams which arc high above and below the orbital plane. From our vantage point, the dynamically-favored pole is likely hidden from view over the entire orbit. The idea of magnetic ``throttling'' of the mass flow through l1 has some credence for very high-field systems, but it appears that too little gas can accumulate in the magnetosphere to be responsible for the episodic accretion behavior exhibited by ar.