2008/02/29 by S. J. Williams, D. R. Gies, T. J. Henry +8 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Binary number #Binary star #Ephemeris #Large Magellanic Cloud #Orbital elements #Orbital period #Photometry (optics) #Small Magellanic Cloud #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/589687
published as Astrophys.J.682:492-498,2008 · 21 pages, 6 figures. Accepted in ApJ. To appear vol. 683, Aug. 10th
arxiv created 2008/04/29 · openalex publication_date 2008/07/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present results from an optical spectroscopic investigation of the massive binary system [L72] LH 54-425 in the LH 54 OB association in the Large Magellanic Cloud. We revise the ephemeris of [L72] LH 54-425 and find an orbital period of 2.24741 ± 0.00004 days. We find spectral types of O3 V for the primary and O5 V for the secondary. We made a combined solution of the radial velocities and previously published V -band photometry to determine the inclination for two system configurations, i = 52 + 2 −3 degrees for the configuration of the secondary star being more tidally distorted and i = 55°± 1° for the primary as the more tidally distorted star. We argue that the latter case is more probable, and this solution yields masses and radii of M 1 = 47 ± 2 M ☉ and R 1 = 11.4 ± 0.1 R ☉ for the primary, and M 2 = 28 ± 1 M ☉ and R 2 = 8.1 ± 0.1 R ☉ for the secondary. Our analysis places LH 54-425 among the most massive stars known. Based on the position of the two stars plotted on a theoretical HR diagram, we find the age of the system to be ~1.5 Myr.