Dynamical Masses for the Large Magellanic Cloud Massive Binary System [L72] LH 54-425

Abstract

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 2.247409 +/- 0.000010 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 degrees for the configuration of the secondary star being more tidally distorted and i = 55 degrees 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_Sun and R_1 = 11.4 +/- 0.1 R_Sun for the primary, and M_2 = 28 +/- 1 M_Sun and R_2 = 8.1 +/- 0.1 R_Sun for the secondary. Our analysis places LH 54-425 amongst 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 about 1.5 Myr.

21 pages, 6 figures. Accepted in ApJ. To appear vol. 683, Aug. 10th

References in corpus (13)

• Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant
• A new calibration of stellar parameters of Galactic O stars
• A Grid of NLTE Line-Blanketed Model Atmospheres of O-type Stars
• Database of Geneva stellar evolution tracks and isochrones for UBVRIJHKLL'M, HST-WFPC2, Geneva and Washington photometric systems
• Dynamical Evidence for a Black Hole in the Microquasar XTE J1550-564
• Evolution towards the critical limit and the origin of Be stars
• The Physical Properties and Effective Temperature Scale of O-type Stars as a Function of Metallicity. II. Analysis of 20 More Magellanic Cloud Stars, and Results from the Complete Sample
• The VLT-FLAMES survey of massive stars: Wind properties and evolution of hot massive stars in the LMC
• Orbits of Four Very Massive Binaries in the R136 Cluster
• Shell formation and star formation in superbubble DEM 192
• Tomographic Separation of Composite Spectra. X. The Massive Close Binary HD 101131
• The Long Period, Massive Binaries HD 37366 and HD 54662: Potential Targets for Long Baseline Optical Interferometry
• A very massive spectroscopic binary in the LH 54 OB association in the LMC

Cited by in corpus (10)

• Rotational mixing in massive binaries: detached short-period systems
• Spitzer SAGE Infrared Photometry of Massive Stars in the Large Magellanic Cloud
• The masses, and the mass discrepancy of O-type stars
• Detailed models of interacting short-period massive binary stars
• Photometric and Spectroscopic Studies of Massive Binaries in the Large Magellanic Cloud. I. Introduction and Orbits for Two Detached Systems: Evidence for a Mass Discrepancy?
• Five More Massive Binaries in the Cygnus OB2 Association
• Apsidal motion and absolute parameters for five LMC eccentric eclipsing binaries
• System Parameters for the Eclipsing B-Star Binary HD 42401
• ASAS Light Curves of Intermediate Mass Eclipsing Binaries and the Parameters of HI Mon
• Accurate fundamental parameters and distance to a massive early-type eclipsing binary in the Danks 2 cluster