Rediscussion of eclipsing binaries. Paper XIV. The F-type system V570 Persei

TL;DR

This study analyzes the F-type eclipsing binary V570 Persei using TESS photometry and spectroscopic data, revealing precise stellar parameters, potential third-body influence, and discrepancies with Gaia measurements.

Contribution

It provides updated stellar masses and radii for V570 Persei based on high-quality TESS data and discusses possible third-body effects and data inconsistencies.

Findings

Stellar masses of 1.449 and 1.350 Msun with small uncertainties.

Detection of a potential faint third body affecting eclipse timing.

Discrepancies between Gaia DR3 and ground-based spectroscopic data.

Abstract

V570 Per is a binary star system containing two F-type stars in a 1.90 d period circular orbit. It shows shallow partial eclipses that were discovered from its Hipparcos light curve. We present an analysis of this system based on two sectors of high-quality photometry from the NASA Transiting Exoplanet Survey Satellite (TESS) mission, and published spectroscopic light ratio and radial velocity measurements. We find masses of 1.449 +/- 0.006 and 1.350 +/- 0.006 Msun, and radii of 1.538 +/- 0.035 and 1.349 +/- 0.032 Rsun. The radius measurements are set by the spectroscopic light ratio and could be improved by obtaining a more precise light ratio. The eclipses in the TESS data arrived 660 +/- 30 s later than expected, suggesting the presence of a faint third body on a wider orbit around the eclipsing system. Small trends in the residuals of the fit to the TESS light curve are attributed to weak starspots. The distance to the system is close to the Gaia DR3 value, but the Gaia spectroscopic orbit is in moderate disagreement with the results from the published ground-based data.