Multiwavelength observations of V479 Andromedae: a close compact binary with an identity crisis

Abstract

We conducted a multi-wavelength study to unveil the properties of the extremely long-period cataclysmic variable V479 And. We performed series of observations, including moderate to high spectral resolution optical spectrophotometry, X-ray observations with Swift, linear polarimetry and near-IR photometry. This binary system is a low-inclination ~ 17^o system with a 0.594093(4) day orbital period. The absorption line complex in the spectra indicate a G8--K0 spectral type for the donor star, which has departed from the zero-age main sequence. This implies a distance to the object of about 4 kpc. The primary is probably a massive 1.1-1.4 Msun magnetic white dwarf, accreting matter at a rate M(dot) > 10^-10 Msun/ yr. This rate can be achieved if the donor star fills its corresponding Roche lobe, but there is little observational evidence for a mass-transfer stream in this system. An alternative explanation is a stellar wind from the donor star, although such a high rate mass loss is not anticipated from a subgiant. If the strongly magnetic white dwarf in V479 And. is confirmed by future observations, the system the polar with the longest observed orbital period. We also discuss the evolutionary state of V479 And.

12 pages, 12 figures, accepted for publication in Astronomy and Astrophysics

References in corpus (9)

• Accurate masses and radii of normal stars: modern results and applications
• The Evolution of Cataclysmic Variables as Revealed by their Donor Stars
• The Donor Stars of Cataclysmic Variables
• Self-Consistent Magnetic Stellar Evolution Models of the Detached, Solar-Type Eclipsing Binary EF Aquarii
• Cyclotron modeling phase-resolved infrared spectroscopy of polars I: EF Eridani
• GALEX and Optical Light Curves of EF Eridanus During a Low State: the Puzzling Source of UV Light
• Determination of the basic parameters of the dwarf nova EY Cygni
• On the orbital period of the magnetic Cataclysmic Variable HS 0922+1333
• The Role of White Dwarfs in Cataclysmic Variable Spin-down

Cited by in corpus (8)

• Evidence for reduced magnetic braking in polars from binary population models
• A catalogue of cataclysmic variables from 20 years of the Sloan Digital Sky Survey with new classifications, periods, trends and oddities
• Galactic Model Parameters and Space Density of Cataclysmic Variables in Gaia Era: New Constraints to Population Models
• Neglected X-ray discovered polars: III. RX J0154.0-5947, RX J0600.5-2709, RX J0859.1+0537, RX J0953.1+1458, and RX J1002.2-1925
• Periodic X-ray sources in the Massive Globular Cluster 47 Tucanae: Evidence for Dynamically Formed Cataclysmic Variables
• Long orbital period pre-polars containing an early K-type donor stars. Bottleneck accretion mechanism in action
• Optical Studies of 8 AM Herculis-Type Cataclysmic Variable Stars
• Revisiting the extremely long-period cataclysmic variables V479 Andromedae and V1082 Sagitarii