Previous abstract Next abstract
The eclipsing magnetic cataclysmic binary DP Leo is a variable soft X-ray source exhibiting eclipses of the emission region on the white dwarf surface by the secondary, variations in the X-ray flux prior to eclipse due to absorption by the accretion stream, and rapid fluctuations likely originating from accretion filaments thermalizing in the surface of the white dwarf. Using available X-ray and other data, we present further evidence to support our hypothesis that systematic variations in the impact position of the accretion stream onto the surface of the white dwarf, relative to the position of the secondary star, are produced through orbital period variations and not due to small oscillations of the white dwarf magnetic pole about an equilibrium position. The mechanism producing the orbital period changes is likely driven by the growth and decay of the magnetic field of the secondary star during solar-like magnetic activity cycles. This is the same mechanism suspected of producing orbital period oscillations in other close binaries with late-type stars.
Monday program listing