2010/11/05 by Simon Albrecht, Joshua N. Winn, Joshua Winn +5 · 76 citations
Biochemistry, Genetics and Molecular Biology · Engineering · Mathematics · Physics and Astronomy · #Acoustics #Aerospace engineering #Astronomy #Astrophysics #Binary number #Engineering #Geomagnetism and Paleomagnetism Studies #Mathematics #Orbit (dynamics) #Period (music) #Physics #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1088/0004-637x/726/2/68
published in The Astrophysical Journal 726(2), 68 (IOP Publishing) · accepted for publication in ApJ
arxiv created 2010/11/05 · openalex publication_date 2010/12/15 · arxiv updated 2015/05/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/08
Binaries are not always neatly aligned. Previous observations of the DI Her system showed that the spin axes of both stars are highly inclined with respect to one another and the orbital axis. Here, we report on a measurement of the spin-axis orientation of the primary star of the NY Cep system, which is similar to DI Her in many respects: it features two young early-type stars (∼6 Myr, B0.5V+B2V), in an eccentric and relatively long-period orbit ( e = 0.48, P = 15 3). The sky projections of the rotation vector and the spin vector are well aligned (β p = 2° ± 4°), in strong contrast to DI Her. Although no convincing explanation has yet been given for the misalignment of DI Her, our results show that the phenomenon is not universal, and that a successful theory will need to account for the different outcome in the case of NY Cep.