2008/02/29 by Mercedes López‐Morales, Mercedes Lopez-Morales, A. Z. Bonanos +1 · 29 citations
Mathematics · Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Geometry #Hypervelocity #Main sequence #Mathematics #Optics #Physics #Rotation (mathematics) #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/592291
published in The Astrophysical Journal 685(1), L47-L50 (IOP Publishing) · 13 pages, 3 figures. ApJL, accepted version
arxiv created 2008/08/19 · openalex publication_date 2008/08/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We measure the projected rotational velocities of the late B-type hypervelocity stars HVS 7 and HVS 8 from high-resolution spectroscopy to be 60 ± 17 km s −1 and 260 ± 70 km s −1 . The "slow" rotation of HVS 7 is in principle consistent with having originated in a binary system, assuming a high inclination angle of the stellar rotation axis. However, the fast rotation of HVS 8 is more typical of single B-type stars. HVS 8 could have therefore been ejected by a mechanism other than that proposed by Hills. We also estimate the effective temperatures and surface gravities for HVS 7 and HVS 8 and obtain an additional measurement of their radial velocities. We find evidence in support of a blue horizontal branch nature for HVS 7 and a main-sequence nature for HVS 8.