2013AJ....145..127I

In this study we present photometric and spectroscopic variation analysis and an orbital period study of a low-mass interacting system OO Aql. Simultaneous solution of the light and radial velocity curves provides us with the determination of a new set of stellar physical parameters for the primary and the secondary companion, M₁= 1.05(2) M_☉, M₂= 0.89(2) M_☉, R ₁= 1.38(2) R_☉, R₂= 1.28(2) R_☉, log (L₁/L_☉) = 0.258, and log (L₂/L_☉) = 0.117, and the separation of the components was determined to be a = 3.333(16) R_☉. Newly obtained parameters yield the distance of the system as 136(8) pc. Analyses of the mid-eclipse times indicate a period increase of (P/{dot}P) = 4 x 10⁷ yr that can be interpreted in terms of the mass transfer (dM/dt) = 5x10^–8 M_☉/yr from the less massive component to the more massive component. Our new solution confirmed that OO Aql is a multiple system in the form of AB + C + D. We found initial astrophysical parameters for the component of the system and its current age to be 8.6 Gyr using a non-conservative stellar evolution model (EV-TWIN code).