The Astrophysical Journal
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 Tcff = 19,800 ± 400 K, and. Thislogg p 4.55 ± 0.10 and log N(He)/N(H) p 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.
Vennes, Stéphane; Kawka, Adéla; and Smith, Jonathan Allyn, "CPD -20 1123 (ALBUS 1) Is A Bright He-B Subdwarf" (2007). Aerospace, Physics, and Space Science Faculty Publications. 249.