Tomographic Separation of Composite Spectra. IX. The Massive Close Binary HD 115071

Abstract

We present the first orbital elements for the massive close binary, HD 115071, a double-lined spectroscopic binary in a circular orbit with a period of 2.73135 +/- 0.00003 days. The orbital semiamplitudes indicate a mass ratio of M_2/M_1 = 0.58 +/- 0.02 and yet the stars have similar luminosities. We used a Doppler tomography algorithm to reconstruct the individual component optical spectra, and we applied well known criteria to arrive at classifications of O9.5 V and B0.2 III for the primary and secondary, respectively. We present models of the Hipparcos light curve of the ellipsoidal variations caused by the tidal distortion of the secondary, and the best fit model for a Roche-filling secondary occurs for an inclination of i = 48.7 +/- 2.1 degrees. The resulting masses are 11.6 +/- 1.1 and 6.7 +/- 0.7 solar masses for the primary and secondary, respectively, so that both stars are very overluminous for their mass. The system is one of only a few known semi-detached, Algol-type binaries that contain O-stars. We suggest that the binary has recently emerged from extensive mass transfer (possibly through a delayed contact and common envelope process).

Submitted to ApJ

References in corpus (2)

• Presupernova Evolution of Rotating Massive Stars II: -- Evolution of the Surface Properties
• Formation of contact in massive close binaries

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• A Compact Array imaging survey of southern bright-rimmed clouds
• Tomographic Separation of Composite Spectra. X. The Massive Close Binary HD 101131
• Galactic Kinematics from a Sample of Young Massive Stars
• Mass and Angular Momentum Transfer in the Massive Algol Binary RY Persei
• Tomographic Separation of Composite Spectra. XI. The Physical Properties of the Massive Close Binary HD 100213 (TU Muscae)
• Eclipsing high-mass binaries I. Light curves and system parameters for CPD-518946, PISMIS24-1 and HD319702