2011/03/08 by John Southworth, K. Pavlovski, E. Tamajo +3
Physics and Astronomy · #Astro and Planetary Science #Astronomy and Astrophysical Research #Binary number #Binary star #Effective temperature #Helium #Photometry (optics) #Spectral line #Spectroscopy #Stars #Stellar classification #Stellar, planetary, and galactic studies #Surface gravity #astro-ph.SR
paper · pdf · doi:10.1111/j.1365-2966.2011.18676.x
Acccepted for publication in MNRAS. 12 pages, 8 tables, 9 figures. XY Cet has been added to the Catalogue of Well-studied Eclipsing Binaries at http://www.astro.keele.ac.uk/~jkt/debdata/debs.html
arxiv created 2011/03/08 · openalex publication_date 2011/05/02 · arxiv updated 2015/05/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present phase-resolved spectroscopy and extensive survey photometry of the detached eclipsing binary system XY Cet, which is composed of two metallic-lined stars. We measure their masses to be 1.773 ± 0.016 and 1.615 ± 0.014 M⊙ and their radii to be 1.873 ± 0.035 and 1.773 ± 0.029 R⊙, resulting in logarithmic surface gravities of 4.142 ± 0.016 and 4.149 ± 0.014 (cgs). We determine effective temperatures of 7870 ± 115 and 7620 ± 125 K. The projected rotational velocities are 34.4 ± 0.4 and 34.1 ± 0.4 km s−1, which are close to synchronous. Theoretical models cannot match all of these properties, but come closest for a solar helium and metal abundance and an age in the region of 850 Myr. We obtain the individual spectra of the two stars by the spectral disentangling method, and compare them to synthetic spectra calculated for the measured effective temperatures and a solar chemical composition. Both stars show enhanced abundances of iron-group elements and clear deficiencies of Ca i and Sc ii, confirming their classification as Am stars. We also find strong overabundances of Zr ii and the rare-earth species La ii, Ce ii and Nd ii, a hallmark of chemically peculiar A stars. XY Cet is a prime candidate for detailed spectroscopic analyses of metallic-lined stars whose masses and radii are known to accuracies of 1–2 per cent.