2008/03/25 by J. Patterson, J. R. Thorstensen, C. Knigge · 47 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Cataclysmic variable star #Galactic halo #Galaxy #Gamma-ray bursts and supernovae #Halo #Intermediate polar #Orbital period #Physics #Population #Radial velocity #Stars #Stellar, planetary, and galactic studies #White dwarf #astro-ph
paper · pdf · doi:10.1086/588615
published in Publications of the Astronomical Society of the Pacific 120(867), 510-522 (Institute of Physics) · 31 pages; 11 figures. Accepted by Publications of the Astronomical Society of the Pacific
arxiv created 2008/03/25 · openalex publication_date 2008/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report a photometric and spectroscopic study of the peculiar cataclysmic variable SDSS 1507+52. The star shows very deep eclipses on the 67-minute orbital period, and those eclipses are easily separable into white-dwarf and hot-spot components. This leads to tight constraints on binary parameters, with M 1 = 0.83(8) M ⊙ , M 2 = 0.057(8) M ⊙ , R 1 = 0.0097(9) R ⊙ , R 2 = 0.097(4) R ⊙ , q = 0.069(2), and i = 83.18(13)°. Such numbers suggest possible membership among the WZ Sge stars, a common type of dwarf nova. The spectroscopic behavior (strong and broad H emission, double-peaked and showing a classic rotational disturbance during eclipse) is also typical. But the star's orbital period is shockingly below the "period minimum" of ∼77 minutes that is characteristic of hydrogen-rich CVs; producing such a strange binary will require some tinkering with the theory of cataclysmic-variable evolution. The proper motion is also remarkably high for a star of its distance, which we estimate from photometry and trigonometric parallax as 230 ± 40 pc. This suggests a transverse velocity of 164 ± 30 km s -1 —uncomfortably high if the star belongs to a Galactic-disk population. These difficulties with understanding its evolution and space velocity can be solved if the star belongs to a Galactic-halo population.