We report extensive spectroscopic and differential V -band photometric observations of the 18.4-day detached double-lined eclipsing binary LV Her ( F9 v ) , which has the highest eccentricity ( e \simeq 0.613 ) among the systems with well-measured properties .
We determine the absolute masses and radii of the components to be M _ { 1 } = 1.193 \pm 0.010 ~ { } M _ { \sun } , M _ { 2 } = 1.1698 \pm 0.0081 ~ { } M _ { \sun } , R _ { 1 } = 1.358 \pm 0.012 ~ { } R _ { \sun } , and R _ { 2 } = 1.313 \pm 0.011 ~ { } R _ { \sun } , with fractional errors of 0.9 % or better .
The effective temperatures are 6060 \pm 150 K and 6030 \pm 150 K , respectively , and the overall metallicity is estimated to be [ m/H ] = +0.08 \pm 0.21 .
A comparison with current stellar evolution models for this composition indicates an excellent fit for an age between 3.8 and 4.2 Gyr , with both stars being near the middle of their main-sequence lifetimes .
Full integration of the equations for tidal evolution is consistent with the high eccentricity , and suggests the stars ’ spin axes are aligned with the orbital axis , and that their rotations should be pseudo-synchronized .
The latter prediction is not quite in agreement with the measured projected rotational velocities .