Detailed Evolutionary Models for Twins in Sight of New Spectral Data: AN Cam, RS Ari, and V455 Aur

TL;DR

This study models the detailed evolutionary history of three twin binary star systems using combined spectroscopic and photometric data, providing precise parameters and evolutionary stages for each system.

Contribution

It presents the first detailed evolutionary scenarios for these systems using high-precision data and the MESA code, highlighting their current states and future evolution.

Findings

AN Cam components have passed the terminal age main-sequence.

RS Ari's primary is in the giant phase, secondary has passed the main-sequence.

V455 Aur's components are still on the main-sequence.

Abstract

We present the evolutionary scenarios for three eclipsing twin ($q(M_2/M_1)\sim$1) binary systems using their combined spectroscopic and photometric data. Using accurate \textit{TESS} photometric data, RV measurements, and spectroscopic data enabled us to calculate fundamental parameters, such as mass and radius, better than 2 percent. The temperature of each component and metallicity of the systems have been obtained via high-resolution spectra. According to our spectral analysis, the metallicity values of AN Cam, RS Ari, and V455 Aur are \text{[M/H]}=\,0.00$\pm$0.12, 0.05$\pm$0.08, and -0.07$\pm$0.07, respectively. Using the derived metallicity for each system, initial orbital parameters and detailed evolutionary status of these three systems are calculated with high precision by using \textsc{mesa}. According to our analysis, both components of AN Cam have passed the terminal age main-sequence, the primary component of RS Ari is in the giant phase while the secondary component has passed the terminal age main-sequence, finally, both components of V455 Aur are still on the main-sequence. The current ages of the three systems AN Cam, RS Ari, and V455 Aur are 3.0, 3.3, and 1.4 Gyrs, respectively, and they will approximately start to transfer mass between components in 400, 250, and 2700 Myrs, respectively.