The Unusual Binary System HD83058 in the OB Association Sco-Cen

• Published in: Astrophysics Vol. 62; no. 2; pp. 183 - 201
• Main Authors: Pogodin, M. A., Drake, N. A., Jilinski, E. G., Pereira, C. B., Galazutdinov, G. A., Herrera, A., Telting, J., Kholtygin, A. F., Ananjevskaja, Yu. K.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-06-2019; Springer; Springer Nature B.V
• Subjects: Astronomy; Astrophysics; Astrophysics and Astroparticles; Astrophysics and Cosmology; Binary stars; Binary system; European Southern Observatory; Observations; Observations and Techniques; Observatories; Orbital elements; Orbits; Phase transitions; Physics; Physics and Astronomy; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Stars, Double; Stellar atmospheres; Stellar models; Stellar rotation; binary systems; orbital elements; spectral variability; separation of spectra of components; HD83058
• ISSN: 0571-7256; 1573-8191
• DOI: 10.1007/s10511-019-09573-8

High-resolution spectroscopic data for the binary system HD83058 located in the OB association Sco-Cen are presented. The observations were made at the ESO and Sierra Armazones (Chile) observatories over 3 seasons: in March 1998, in 2007-2009, and in May 2013. A total of 41 spectra of the object were obtained. An analysis of the radial velocities of the lines from both system component yielded the orbital elements and an orbital period of P = 2.3650804 ± 0.0000034 days was found. Using a model of stellar atmospheres we separated the spectra of the two components and found their parameters to be T
eff
= 25700 ± 400 K, logg = 4.27 ± 0.05, and T
eff
= 19200 ± 600 K, logg = 4.03 ± 0.20 for components A and B, respectively. We confirmed the presence of moving local features in the profiles of the SiIII lines in the spectrum of component A which may be associated either with pulsation activity of the star or with the rotation of spot-like inhomogeneities on its surface. We found that the lines in the spectrum of component B have another type of variability in which the width and depth of almost all the atmospheric lines change in opposite phase on individual dates. It was found that the system is substantially asynchronous. We assume that the desynchronization of the system may arise from gravitational interactions of the system with a third body, since the density of stars within the OB association must be much higher than usual.