The Applegate mechanism in Post-Common-Envelope Binaries: Investigating the role of rotation

摘要: Eclipsing time variations (ETVs) are observed in many close binary systems. In particular, for several post-common-envelope binaries (PCEBs) that consist of a white dwarf and main sequence star, the O-C diagram suggests real or apparent orbital period driven by Jupiter-mass planets as result magnetic activity, so-called Applegate mechanism. The latter explains changes stellar quadrupole moment due to activity. We explore feasibility driving ETVs via mechanism sample PCEB systems, including range different rotations. Using MESA code we evolve 12 stars with masses rotation rates. apply simple dynamo model their radial profiles investigate on which scale predicted activity cycle matches modulation period, quantify uncertainty, further calculate required energies drive que show is energetically feasible 5 note these systems highest rate compared critical main-sequence star. results suggest ratio physical star an important indicator Applegate's mechanism, but exploring larger samples will be necessary probe this hypothesis.