Asiago eclipsing binaries program

Abstract

The orbit and fundamental physical parameters of the double-lined eclipsing binary V505 Per are derived by means of Echelle highresolution and high S /N spectroscopy, and B, V photometry. In addition, effective temperatures, gravities, rotational velocities, and metallicities of both components are also obtained from atmospheric χ 2 analysis, showing an excellent match with the results of the orbital solution. An E B−V ≤ 0.01 mag upper limit to the reddening is derived from intensity analysis of interstellar NaI (5890.0 & 5895.9 Å) and KI (7699.0 Å) lines. The distance to the system computed from orbital parameters (60.6 ± 1 pc) is identical to the newly re-reduced Hipparcos parallax (61.5 ± 1.9 pc). The masses of the two components (M 1 = 1.2693 ± 0.0011 and M 2 = 1.2514 ± 0.0012 M ) place them in the transition region between convective and radiative stellar cores of the HR diagram, with the more massive of the two already showing the effect of evolution within the main sequence band (T 1 = 6512 ± 21 K, T 2 = 6462 ± 12 K, R 1 = 1.287 ± 0.014, R 2 = 1.266 ± 0.013 R ). This makes this system particularly relevant to theoretical stellar models as a test of the overshooting. We compare the firm observational results for V505 Per component stars with the predictions of various libraries of theoretical stellar models (BaSTI, Padova, Granada, Yonsei-Yale, Victoria-Regina), as well as with BaSTI models computed specifically for the masses and chemical abundances of V505 Per. We find that the overshooting at the masses of V505 Per component stars is already pretty low, but not nil, and it is described by efficiencies λ OV = 0.093 and 0.087 for the 1.27 and 1.25 M components, respectively. According to the computed BaSTI models, the age of the system is ∼0.9 Gyr, and the element diffusion

Modelling binary stars: age, helium abundance and convection parameters

“…We predict that this system is very young, with an age of 0.7–0.8 Gyr, in relatively good agreement with Tomasella et al (), who found 0.9 Gyr. However, as for VZ Hya, the mixing‐length parameters are subsolar and Δ Y /Δ Z is higher than the solar value (∼4 ± 1.5).…”

Asiago eclipsing binaries program IV. SZ Camelopardalis, aβ Cephei pulsator in a quadruple, eclipsing system

“…However, empirical constraints on these features remain of high priority, despite steady improvement in observational techniques and capabilities (Hilditch 2004). Eclipsing binaries of the detached type are a great resource for obtaining accurate values of stellar masses, radii, and luminosities (Andersen 1991;Torres et al 2010). Given that the component stars have the same age and initial chemical composition, eclipsing binaries have been extensively used to test predictions of stellar models (e.g.…”

A Large Stellar Evolution Database for Population Synthesis Studies. Iv. Integrated Properties and Spectra

“…The database has been extensively tested against observations of local stellar populations and eclipsing binary systems (see, for some ex-amples, the tests presented in Papers I, II and III; Tomasella et al 2008). In its present form BaSTI can be used to investigate resolved stellar populations, and indeed it has been widely employed in studies of Galactic and extragalactic resolved star clusters (see, e.g.…”