Non-synchronous rotations in massive binary systems. HD93343 revisited

Abstract

Context. Most massive stars are in binary or multiple systems. Several massive stars have been detected as doublelined spectroscopic binaries and among these, the OWN Survey has detected a non-negligible number whose components show very different spectral line broadening (i.e., projected rotational velocities). This fact raises a discussion about the contributing processes, such as angular-momentum transfer and tidal forces. Aims. We seek to constrain the physical and evolutionary status of one of such systems, the O+O binary HD 93343. Methods. We analyzed a series of high-resolution multiepoch optical spectra to determine the orbital parameters, projected rotational velocities, and evolutionary status of the system. Results. HD 93343 is a binary system comprised of two O7.5 Vz stars that each have minimum masses of approximately 22 Mo in a wide and eccentric orbit (e = 0.398$\pm$0.004; P=50.432$\pm$0.001 d). Both stars have very similar stellar parameters, and hence ages. As expected from the qualitative appearance of the combined spectrum of the system, however, these stars have very different projected rotational velocities (~65 and ~325 km/s, respectively). Conclusions. The orbits and stellar parameters obtained for both components seem to indicate that their youth and relative separation is enough to discard the effects of mass transfer and tidal friction. Thus, non-synchronization should be intrinsic to their formation.

arXiv comment9 pages, 7 figures. Accepted to Astronomy & Astrophysics

References in corpus (38)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• The SIMBAD astronomical database
• Binary interaction dominates the evolution of massive stars
• Stellar Multiplicity
• A new calibration of stellar parameters of Galactic O stars
• A Computational Guide to Physics of Eclipsing Binaries. Paper I. Demonstrations and Perspectives
• Rotating Massive Main-Sequence Stars I: Grids of Evolutionary Models and Isochrones
• The rotation rates of massive stars: the role of binary interaction through tides, mass transfer and mergers
• The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars
• Atmospheric NLTE-Models for the Spectroscopic Analysis of Blue Stars with Winds. II. Line-Blanketed Models
• The Galactic O-Star Spectroscopic Survey. I. Classification System and Bright Northern Stars in the Blue-Violet at R~2500
• The IACOB project: I. Rotational velocities in Northern Galactic O and early B-type stars revisited. The impact of other sources of line-broadening
• Formation of contact in massive close binaries
• The VLT-FLAMES Tarantula Survey XII. Rotational velocities of the single O-type stars
• Constraining the mass transfer in massive binaries through progenitor evolution models of Wolf-Rayet+O binaries
• BONNSAI: a Bayesian tool for comparing stars with stellar evolution models
• The Galactic O-Star Spectroscopic Survey (GOSSS). III. 142 additional O-type systems
• Fundamental parameters of Galactic luminous OB stars VI. Temperatures, masses and WLR of Cyg OB2 supergiants
• Equipotential Surfaces and Lagrangian points in Non-synchronous, Eccentric Binary and Planetary Systems
• A comparison of evolutionary tracks for single Galactic massive stars
• The IACOB project. V. Spectroscopic parameters of the O-type stars in the modern grid of standards for spectral classification
• The VLT-FLAMES Tarantula Survey XXI. Stellar spin rates of O-type spectroscopic binaries
• Spectroscopic and physical parameters of Galactic O-type stars. III. Mass discrepancy and rotational mixing
• Distance and the Initial Mass Function of Young Open Clusters In The Eta Carina Nebula: Tr 14 and Tr 16
• The IACOB project: A grid-based automatic tool for the quantitative spectroscopic analysis of O-stars
• Nitrogen line spectroscopy of O-stars -- I. Nitrogen III emission line formation revisited
• High resolution optical spectroscopy of Plaskett's star
• Orbital and physical properties of the $\sigma$ Ori Aa,Ab,B triple system
• The VLT-FLAMES Tarantula Survey XXVI: Properties of the O-dwarf population in 30 Doradus
• The VLT-FLAMES Tarantula Survey. XIII: On the nature of O Vz stars in 30 Doradus
• What Sets the Initial Rotation Rates of Massive Stars?
• Spectroscopic evolution of massive stars on the main sequence
• A third massive star component in the σ Orionis AB system
• Optical spectroscopy of X-Mega targets in the Carina nebula - VII On the multiplicity of Tr 16-112, HD 93343 and HD 93250
• Tomographic Separation of Composite Spectra. X. The Massive Close Binary HD 101131
• Spectral classification and properties of the O Vz stars in the Galactic O-Star Spectroscopic Survey (GOSSS)
• The Long Period, Massive Binaries HD 37366 and HD 54662: Potential Targets for Long Baseline Optical Interferometry

Cited by in corpus (3)

• The Villafranca catalog of Galactic OB groups. II. From Gaia DR2 to EDR3 and ten new systems with O stars
• Rotational synchronisation of B-type binaries in 30 Doradus
• Micro-turbulence across the Hertzsprung-Russell diagram. Observational constrains for stars in the MW