The low-mass interacting binary system OO Aql revisited: a new quadruple system

TL;DR

This study provides a comprehensive analysis of the low-mass binary system OO Aql, revealing its physical parameters, orbital period changes, and confirming its quadruple system nature through combined photometric and spectroscopic data.

Contribution

It offers the first detailed physical parameters and orbital analysis of OO Aql as a quadruple system, including period variation and evolutionary status.

Findings

Determined stellar masses, radii, and luminosities of the components.

Identified a period increase indicating mass transfer between stars.

Confirmed OO Aql as a quadruple system with initial age of 8.6 Gyr.

Abstract

In this study we present photometric and spectroscopic variation analysis and orbital period study of a low-mass interacting system OO Aql. Simultaneous solution of the light and radial velocity curves provide us a determination of new set of stellar physical parameters for the primary and the secondary companion as M$_{1}$ = 1.05(2) M$_{\odot}$, M$_{2}$ = 0.89(2) M$_{\odot}$, R$_{1}$ = 1.38(2) R$_{\odot}$, R$_{2}$ = 1.28(2) R$_{\odot}$, $\log{(L_1/L_{\odot})} = 0.258$ and $\log{(L_2/L_{\odot})} = 0.117$ and the separation of the components were determined a = 3.333(16) R$_{\odot}$. Newly obtained parameters yield the distance of the system as 136(8) pc. Analyses of the mid-eclipse times indicate a period increase of $\frac{P}{\dot{P}}=4\times 10^{7}$ yr that can be interpreted in terms of the mass transfer $\frac{dM}{dt}=5\times 10^{-8}$ M$_{\odot}$/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 nonconservative stellar evolution model (EV-TWIN code).