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

MORRELL, N. I.; FERRERO, G. A.; C. PUTKURI; C. PUTKURI; SIMÓN-DÍAZ, S.; SIMÓN-DÍAZ, S.; ARIAS, J. I.; ARIAS, J. I.; GAMEN, R.; BARBA, R.; SOLIVELLA, G. ; GAMEN, R.; BARBA, R.; SOLIVELLA, G. ; MORRELL, N. I.; FERRERO, G. A.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2018 p. 174 - 183

0004-6361

Context. Most massive stars are in binary or multiple system. Several of them are detected as double-lined spectroscopic binaries andamong 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 arises the discussion about the processes acting in, as angular-momentum transfer, tidalforces, etc.Aims. To constrain the physical and evolutionary status of one of such systems, the O+O binary HD 93343.Methods. We analyzed high resolution optical spectra to determine the orbital parameters, projected rotational velocities and evolu-tionary status of the system.Results. HD 93343 is a binary system comprised of two very similar O7.5 Vz stars, with minimum masses around 22 M each, in awide and eccentric orbit (e = 0.398 ±0.004; P=50.432 ±0.001 d). Both stars have very similar stellar parameters (and hence ages) but,as expected from the qualitative appearence of the combined spectrum of the system, quite 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 separationis enough to discard the effects of mass-transfer and tidal friction. Thus, the non- synchronization should be intrinsic to their formation.