Jinzhao Yuan | Searcharxiv

arXiv2015

Z Draconis with two companions in a 2:1 mean-motion resonance

All available mid-eclipse times of the eclipsing binary Z Draconis are analysed, and three sets of cyclic variations with periods of 20.1, 29.96 and 59.88 yr are found. The low-amplitude variations with the period of 20.1 yr may be attributed to the unavoidable and slight imperfection in the double-Keplerian model, which gives the periods of 29.96 and 59.88 yr. Interestingly, the Z Draconis system is close to a 2:1 mean-motion resonance, or 6:3:2 mean-motion resonance if the period of 20.1 yr is true. We also find that the best solutions tend to give the minimum eccentricities. Based on Kepler's third law, the outermost companion has the minimum mass of $\sim0.77M_{\bigodot}$, whereas the middle companion is an M dwarf star with a mass of $\sim0.40M_{\bigodot}$, suggesting that Z Draconis is a general N-body system.

astro-ph.SR↗

arXiv2010

First photometric study of the eclipsing binary PS Persei

The CCD photometric observations of the eclipsing binary PS Persei (PS Per) were obtained on two consecutive days in 2009. The 2003 version Wilson-Devinney code was used to analyze the first complete light curves in $V$ and $R$ bands. It is found that PS Per is a short-period Algol-type binary with the less massive component accurately filling its inner critical Roche lobe. The mass ratio of $q=0.518$ and the orbital inclination of $i=89.^{\circ}86$ are obtained. On the other hand, based on all available times of primary light minimum including two new ones, the orbital period has been improved.

astro-ph.SR↗