2008/05/12 by C. Cameron, Christopher J. Cameron, Hideyuki Saio +11 · 45 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Geometry #Opacity #Optics #Photometry (optics) #Physics #Rotation (mathematics) #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/590369
published in The Astrophysical Journal 685(1), 489-507 (IOP Publishing) · 36 pages, 16 figures, 3 tables, accepted for publication in ApJ
arxiv created 2008/05/12 · openalex publication_date 2008/09/18 · arxiv updated 2009/12/01 · openalex created_date 2019/06/27 · openalex updated_date 2026/08/05
The MOST ( Microvariability and Oscillations of Stars ) satellite has discovered SPBe (slowly pulsating Be) oscillations in the stars HD 127756 (B1/B2 Vne) and HD 217543 (B3 Vpe). For HD 127756, 30 significant frequencies are identified from 31 days of nearly continuous photometry; for HD 217543, up to 40 significant frequencies from 26 days of data. In both cases, the oscillations fall into three distinct frequency ranges, consistent with models of the stars. The variations are caused by nonradial g -modes (and possibly r -modes) distorted by rapid rotation and excited by the opacity mechanism near the iron opacity bump. A comparison of pulsation models and observed frequency groups yields a rotation frequency for each star, independently of v sin i . The rotation rates of these stars, as well as those of the SPBe stars previously discovered by MOST , HD 163868 and β CMi, are all close to their critical values.