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Aims. We present the results of our detailed spectroscopic and photometricanalysis of two previously unknown < 1 M{_\sun} detached eclipsing binaries:ASAS J045304-0700.4 and ASAS J082552-1622.8.  Methods. With the HIgh Resolution Echelle Spectrometer (HIRES) on the Keck-Itelescope, we obtained spectra of both objects covering large fractions oforbits of the systems. We also obtained V and I band photometry with the 1.0-mElizabeth telescope of the South African Astronomical Observatory (SAAO). Theorbital and physical parameters of the systems were derived with the PHOEBE andJKTEBOP codes. We investigated the evolutionary status of both binaries withseveral sets of widely-used isochrones.  Results. Our modelling indicates that (1) ASAS J045304-0700.4 is an old,metal-poor, active system with component masses of M1 = 0.8452 \pm 0.0056M$_\odot$, M2 = 0.8390 \pm 0.0056 M$_\odot$ and radii of R1 = 0.848 \pm 0.005R$_\odot$ and R2 = 0.833 \pm 0.005 R$_\odot$, which places it at the end of theMain Sequence evolution - a stage rarely observed for this type of stars. (2)ASAS J082552-1622.8 is a metal-rich, active binary with component masses of M1= 0.703 \pm 0.003 M$_\odot$, M2 = 0.687 \pm 0.003 M$_\odot$ and radii of R1 =0.694(+0.007-0.011) R$_\odot$ and R2 = 0.699(+0.011-0.014) R$_\odot$. Bothsystems show significant out-of-eclipse variations, probably owing to large,cold spots. we also investigated the influence of a third light in the secondsystem.

astronomy and astrophysics

Orbital and physical parameters of eclipsing binaries from the ASAS  catalogue -- II. Two spotted M < 1 M$_\odot$ systems at different  evolutionary stages