Spectroscopic observations are reported for the 2.75 day , double-lined , detached eclipsing binary EPIC 219552514 located at the turnoff of the old nearby open cluster Ruprecht 147 .
A joint analysis of our radial velocity measurements and the K2 light curve leads to masses of M _ { 1 } = 1.509 ^ { +0.063 } _ { -0.056 } ~ { } M _ { \sun } and M _ { 2 } = 0.649 ^ { +0.015 } _ { -0.014 } ~ { } M _ { \sun } for the primary and secondary , along with radii of R _ { 1 } = 2.505 ^ { +0.026 } _ { -0.031 } ~ { } R _ { \sun } and R _ { 2 } = 0.652 ^ { +0.013 } _ { -0.012 } ~ { } R _ { \sun } , respectively .
The effective temperatures are 6180 \pm 100 K for the F7 primary and 4010 \pm 170 K for the late K secondary .
The orbit is circular , and the stars ’ rotation appears to be synchronized with the orbital motion .
This is the third eclipsing system analyzed in the same cluster , following our earlier studies of EPIC 219394517 and EPIC 219568666 .
By comparison with stellar evolution models from the PARSEC series , we infer an age of 2.67 ^ { +0.39 } _ { -0.55 } Gyr that is consistent with the estimates for the other two systems .
EPIC 219552514 is a hierarchical triple system , with the period of the slightly eccentric outer orbit being 463 days .
The unseen tertiary is either a low-mass M dwarf or a white dwarf .