The eccentric massive binary V380 Cyg: revised orbital elements and interpretation of the intrinsic variability of the primary component. Issue 4 (14th January 2014)

• Record Type: Journal Article
• Authors: Tkachenko, A.; Degroote, P.; Aerts, C.; Pavlovski, K.; Southworth, J.; Pápics, P. I.; Moravveji, E.; Kolbas, V.; Tsymbal, V.; Debosscher, J.; Clémer, K.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 438:Issue 4(2014)
• Page Start: 3093
• Page End: 3110
• Publication Date: 2014-01-14
• Subjects: binaries: eclipsing -- stars: fundamental parameters -- stars: individual: V380 Cyg -- stars: oscillations -- stars: variables: general; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stt2421
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: We present a detailed analysis and interpretation of the high-mass binary V380 Cyg, based on high-precision space photometry gathered with the Kepler space mission as well as high-resolution ground-based spectroscopy obtained with the HERMES spectrograph attached to the 1.2 m Mercator telescope. We derive a precise orbital solution and the full physical properties of the system, including dynamical component mass estimates of 11.43 ± 0.19 and 7.00 ± 0.14 M⊙ for the primary and secondary, respectively. Our frequency analysis reveals the rotation frequency of the primary in both the photometric and spectroscopic data and additional low-amplitude stochastic variability at low frequency in the space photometry with characteristics that are compatible with recent theoretical predictions for gravity-mode oscillations excited either by the convective core or by sub-surface convective layers. Doppler imaging analysis of the silicon lines of the primary suggests the presence of two high-contrast stellar surface abundance spots which are located either at the same latitude or longitude. Comparison of the observed properties of the binary with present-day single-star evolutionary models shows that the latter are inadequate and lack a serious amount of near-core mixing.