2003/06/03 by R. Staubert, S. Friedrich, Susanne Friedrich +7 · 16 citations
Earth and Planetary Sciences · Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Cataclysmic variable star #High-pressure geophysics and materials #Intermediate polar #Light curve #Photometry (optics) #Physics #Polar #Stars #Stellar, planetary, and galactic studies #White dwarf #astro-ph
paper · pdf · doi:10.1051/0004-6361:20030851
published in Astronomy and Astrophysics 407(3), 987-998 (EDP Sciences) · 12 pages, 10 figures, 6 tables accepted by A&A
arxiv created 2003/06/03 · openalex publication_date 2003/08/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The magnetic Cataclysmic Variable (mCV) V1432 Aql (RX J1940.1–1025) belongs to the four-member subclass of near-synchronous polars with a slight non-synchronism (<2%) between the spin period of the white dwarf and the binary period. In these systems the accretion geometry changes periodically with phase of the beat cycle. We present the application of a dipole accretion model for near-synchronous systems developed by Geckeler & Staubert (1997a) to extended optical and X-ray data. We detect a significant secular change of the white dwarf spin period in V1432 Aql of s/s from the optical data set alone. This corresponds to a synchronization time scale yr, comparable to the time scale of 170 yr for V1500 Cyg. The synchronization time scale in V1432 Aql is in excellent agreement with the theoretical prediction from the dominating magnetic torque in near-synchronous systems. We also present period analyses of optical CCD photometry and RXTE X-ray data, which argue against the existence of a 4000 s period and an interpretation of V1432 Aql as an intermediate polar. The dipole accretion model also allows us to constrain the relevant parameters of the accretion geometry in this system: the optical data allow an estimate of the dimensionless parameter , with a lower limit for the threading radius of (68% confidence).