Rediscussion of eclipsing binaries. Paper XVII. The F-type twin system CW Eridani

Abstract

CW Eri is a detached eclipsing binary system of two F-type stars with an orbital period of 2.728 d. Light curves from two sectors of observations with the Transiting Exoplanet Survey Satellite (TESS) and previously published radial velocity data are analysed to determine the system's physical properties to high precision. We find the masses of the two stars to be $1.568 \pm 0.016$ Msun and $1.314 \pm 0.010$ Msun, the radii to be $2.105 \pm 0.007$ Rsun and $1.481 \pm 0.005$ Rsun, and the system's orbit to have an eccentricity of $0.0131 \pm 0.0007$. The quality of the TESS photometry allows the definition of a new high-precision orbital ephemeris, however no evidence of pulsation is found. We derive a distance to the system of $191.7\pm 3.8$ pc, a value consistent with the Gaia DR3 parallax which yields a distance of $187.9^{+0.6}_{-0.9}$ pc. The measured parameters of both stellar components are found to be in agreement with theoretical predictions for a solar chemical composition and an age of 1.7 Gyr.