VV Corvi: a benchmark eclipsing binary in a hierarchical multiple system

Abstract Eclipsing binaries in hierarchical multiple systems provide fundamental laboratories for testing stellar evolution models, tidal interactions, and the dynamical evolution of multiple stellar systems. We present a new analysis of the detached eclipsing binary VV Crv, a member of the hierarchical multiple system STF 1669, based on TESS photometry, published radial velocities, eclipse timings, and archival astrometry. We derive a revised apsidal-motion solution from eclipse-timing variations, with a period of 241 ± 23 yr, and obtain accurate absolute parameters of M1 = 1.970 ± 0.009 M⊙, M2 = 1.497 ± 0.007 M⊙, R1 = 3.329 ± 0.018 R⊙, R2 = 1.646 ± 0.022 R⊙, T1 = 6500 ± 300 K, T2 = 6638 ± 300 K, L1 = 17.8 ± 3.3 L⊙, and L2 = 4.7 ± 0.9 L⊙. Comparison with MIST evolutionary models indicates a slightly supersolar metallicity of [Fe/H] = +0.25 ± 0.05 and an age of 1.09 ± 0.05 Gyr. The observed internal-structure constant is in good agreement with theoretical predictions. The astrometric properties of STF 1669AB are consistent with VV Crv being part of a hierarchical multiple system that also includes the astrometric component HD 110318 and the distant visual companion BD−12 3675, with an outer orbital period of several thousand years. The persistence of a significant orbital eccentricity despite the evolved age of this close binary system suggests that long-term dynamical perturbations within the wider hierarchical configuration may have played an important role in its evolution.