The orbit and physical parameters of the previously unsolved double-lined eclipsing binary V570 Per , discovered by the Hipparcos satellite , are derived using high resolution Echelle spectroscopy and B , V photo-electric photometry .
The metallicity from \chi ^ { 2 } analysis of the spectra is [ M/H ] =+0.02 \pm 0.03 , and reddening from interstellar NaI and KI absorption lines is E _ { B - V } =0.023 \pm 0.007 .
V570 Per is a well detached system , with shallow eclipses due to low orbital inclination and no sign of chromospheric activity .
The two components have masses of 1.449 \pm 0.006 and 1.350 \pm 0.006 M _ { \odot } and spectral types F3 and F5 , respectively .
They are both still within the Main Sequence band ( T _ { 1 } =6842 \pm 25 K , T _ { 2 } =6562 \pm 25 K from \chi ^ { 2 } analysis , R _ { 1 } =1.523 \pm 0.030 , R _ { 2 } =1.388 \pm 0.019 R _ { \odot } derived forcing the orbital solution to conform to the spectroscopic light ratio ) and are dynamically relaxed to co-rotation with the orbital motion ( V _ { rot } \sin i _ { 1 , 2 } =40 and 36 ( \pm 1 ) km sec ^ { -1 } ) .
The distance to V570 Per obtained from the orbital solution is 123 \pm 2 pc , in excellent agreement with the revised Hipparcos distance of 123 \pm 11 pc .
The observed properties of V570 Per components are compared to available families of stellar evolutionary tracks , and in particular to BaSTI models computed on purpose for exactly the observed masses and varied chemical compositions .
This system is interesting since both components have their masses in the range where the efficiency of convective core overshooting has to decrease with the total mass as a consequence of the decreasing size of the convective core during the central H-burning stage .
Our numerical simulations show that , in order to match all empirical constraints including also the spectroscopical measurements , a small but not null overshooting is required , with efficiencies of \lambda _ { OV } =0.14 and 0.11 for the 1.449 and 1.350 M _ { \odot } components , respectively .
This confirms the finding of Paper II on the similar system V505 Per .
At the \approx 0.8 Gyr age of the system , the element diffusion has reduced the surface metallicity of the models from the initial [ M/H ] =+0.17 to [ M/H ] =+0.02 , in perfect agreement with the spectroscopically derived [ M/H ] =+0.02 \pm 0.03 value .