2007/08/20 by Stephane Vennes, S. Vennes, A. Kawka +3 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Balmer series #Emission spectrum #Gamma-ray bursts and supernovae #Horizontal branch #Metallicity #Physics #Red giant #Spectral line #Stars #Stellar, planetary, and galactic studies #Subdwarf #White dwarf #astro-ph
paper · pdf · doi:10.1086/522605
Accepted for publication in The Astrophysical Journal Letters
arxiv created 2007/08/20 · openalex publication_date 2007/09/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Based on photometric and astrometric data it has been proposed that Albus 1 (also known as CPD -20 1123) might be a hot white dwarf similar to G191-B2B or, alternatively, a hot subdwarf. We obtained a series of optical spectra showing that CPD -20 1123 is a bright He-B subdwarf. We analyzed the H I Balmer and He I line spectra and measured T eff = 19,800 ± 400 K, log g = 4.55 ± 0.10, and log N (He)/ N (H) = 0.15 ± 0.15. This peculiar object belongs to a family of evolved helium-rich stars that may be the products of double-degenerate mergers, or, alternatively, the products of post horizontal- or giant-branch evolution.