DD Mon and XY UMa: CCD Photometry and modelling of two close binary systems with solar-type components

TL;DR

This study presents CCD photometry and modeling of two close binary systems with solar-type stars, analyzing their light curves and comparing photometric and spectroscopic mass ratio determination methods, including a new spot model for XY UMa.

Contribution

The paper provides detailed photometric analysis and modeling of DD Mon and XY UMa, introducing a new spot model for XY UMa and comparing different mass ratio determination techniques.

Findings

Derived geometric and photometric elements for DD Mon and XY UMa.

Compared photometric and spectroscopic mass ratio methods.

Proposed a new spot model for XY UMa.

Abstract

We present our ground-based CCD observations of the close binary systems DD Mon and XY UMa in B, V, R and I bands. The light curves are analyzed using the Wilson-Devinney code (W-D) for the derivation of the geometric and photometric elements of the systems. We compare the methods of photometric and spectroscopic mass ratio determination in these binaries, as a function of all typical difficulties, which arise during the analysis of such systems (light curve asymmetries, third light etc). Finally, a new spot model is suggested for the eclipsing system XY UMa, which belongs to the RS CVn type of active binaries.