We present the first full orbital and physical analysis of HD 187669 , recognized by the All-Sky Automated Survey ( ASAS ) as the eclipsing binary ASAS J195222-3233.7 .
We combined multi-band photometry from the ASAS and SuperWASP public archives and 0.41-m PROMPT robotic telescopes with our high-precision radial velocities from the HARPS spectrograph .
Two different approaches were used for the analysis : 1 ) fitting to all data simultaneously with the WD code , and 2 ) analysing each light curve ( with jktebop ) and RVs separately and combining the partial results at the end .
This system also shows a total primary ( deeper ) eclipse , lasting for about 6 days .
A spectrum obtained during this eclipse was used to perform atmospheric analysis with the moog and sme codes in order to constrain physical parameters of the secondary .

We found that ASAS J195222-3233.7 is a double-lined spectroscopic binary composed of two evolved , late-type giants , with masses of M _ { 1 } = 1.504 \pm 0.004 and M _ { 2 } = 1.505 \pm 0.004 M _ { \odot } , and radii of R _ { 1 } = 11.33 \pm 0.28 and R _ { 2 } = 22.62 \pm 0.50 R _ { \odot } , slightly less metal abundant than the Sun , on a P = 88.39 d orbit .
Its properties are well reproduced by a 2.38 Gyr isochrone , and thanks to the metallicity estimation from the totality spectrum and high precision in masses , it was possible to constrain the age down to 0.1 Gyr .
It is the first so evolved galactic eclipsing binary measured with such a good accuracy , and as such is a unique benchmark for studying the late stages of stellar evolution .