Non-synchronous rotations in massive binary systems. HD 93343 revisited

Putkuri, C.; Gamen, R.; Morrell, N. I.; Simón-Díaz, S.; Barbá, R. H.; Ferrero, G. A.; Arias, J. I.; Solivella, G.
Bibliographical reference

Astronomy and Astrophysics, Volume 618, id.A174, 9 pp.

Advertised on:
10
2018
Number of authors
8
IAC number of authors
1
Citations
7
Refereed citations
6
Description
Context. Most massive stars are in binary or multiple systems. Several massive stars have been detected as double-lined 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 M⊙ in a wide and eccentric orbit (e = 0.398±0.004; P = 50.432±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-1, 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. This work is based on observations collected at Complejo Astronómico El Leoncito, Las Campanas Observatory, and La Silla Observatory.
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Physical properties and evolution of Massive Stars

This project aims at the searching, observation and analysis of massive stars in nearby galaxies to provide a solid empirical ground to understand their physical properties as a function of those key parameters that gobern their evolution (i.e. mass, spin, metallicity, mass loss, and binary interaction). Massive stars are central objects to

Sergio
Simón Díaz