author={Changqing Luo and Xiao Zhang and Licai Deng and Kun Wang and Yangping Luo},
  journal={The Astronomical Journal},
We present multi-color CCD photometry of the neglected contact binary XZ Leo. Completely covered VRI band light curves and four times of minimum light were obtained. Combining the photometric and previously published radial-velocity data, a revised photometric analysis was carried out for the binary system by applying the Wilson–Devinney code. With a hot spot placed on the massive primary component near the neck region of the common envelope, the light curves were satisfactorily modeled. The… 

Figures and Tables from this paper

Photometric studies for two contact binaries: V532 Monocerotis and GU Orionis

We present photometry and spectroscopy data for V532 Mon and GU Ori, observed in 2011 and 2016. From the spectral observations, the spectral types are determined to be F5V for V532 Mon and G0V for GU

Photometric Study and Absolute Parameter Estimation of Six Totally Eclipsing Contact Binaries

High precision CCD observations of six totally eclipsing contact binaries were presented and analyzed. It is found that only one target is an A-type contact binary (V429 Cam), while the others are

Rapid Light-curve Changes and Probable Flip-flop Activity of the W UMa-type Binary V410 Aur

New photometric observations of a W UMa system, V410 Aur, were carried out over 10 nights from 2014 December 19 to 2015 February 8, from which four sets of light curves were obtained. The light

Orbital period cut-off of W UMa-type contact binaries

Period cut-off and period–colour relation are two special characters of W UMa-type contact binaries. In the past, many authors noted these two properties, however, a comprehensive study was still

Starspots in contact and semi-detached binary systems

  • S. Kouzuma
  • Physics
    Publications of the Astronomical Society of Japan
  • 2019
We investigated the statistical properties of both cool and hot starspots in eclipsing binary stars. The starspot and binary parameters for contact and semi-detached systems were collected from

Light curve analysis of six totally eclipsing W UMa binaries

We analyze multicolor light curves of six totally eclipsing, short-period W UMa binaries and derive, for the first time, their orbital and stellar parameters. The mass ratios are established

Different evolutionary pathways for the two subtypes of contact binaries

Secondary components of W UMa-type contact binaries (CBs) have many special properties, two of them are excess in radius and luminosity. In order to make these specialties clear, we propose radial


The historical development of binary star light curve models is traced from the early 1900s to the present, with emphasis on recent progress. A major break with tradition occurred about 1970 when

Radial Velocity Studies of Close Binary Stars. VI.

Radial velocity measurements and sine-curve fits to the orbital velocity variations are presented for the sixth set of 10 close binary systems: SV Cam, EE Cet, KR Com, V410 Cyg, GM Dra, V972 Her, ET

New limb-darkening coefficients for modeling binary star light curves

We present monochromatic, passband-specific, and bolometric limb-darkening coefficients for a linear as well as nonlinear logarithmic and square root limb-darkening laws. These coefficients,

A possible relation between the period change and the mass ratio for W-type contact binaries

Orbital period changes of eight W-type contact binaries (TY Boo, BH Cas, AD Cnc, TX Cnc, RZ Com, LS Del, BB Peg and AA UMa) are presented based on the analysis of their O-C curves. It is found that

Are overcontact binaries undergoing thermal relaxation oscillation with variable angular momentum loss

Orbital period variations of five W-type overcontact binaries, GW Cep, VY Cet, V700 Cyg, EM Lac and AW Vir, are presented based on the analysis of all available times of light minimum. It is

Orbital period changes of contact binary systems: direct evidence for thermal relaxation oscillation theory

Orbital period changes of ten contact binary systems (S Ant, epsilon CrA, EF Dra, UZ Leo, XZ Leo, TY Men, V566 Oph, TY Pup, RZ Tau and AG Vir) are studied based on the analysis of their O-C curves.

Eccentric orbit generalization and simultaneous solution of binary star light and velocity curves

The computation of binary star light and radial velocity curves are discussed, including the effects of eccentric orbits and nonsynchronous rotation. Logical relations needed to impose physical

Accuracy and efficiency in the binary star reflection effect

The geometric and irradiation heating problems for the binary star reflection effect theory are developed in terms of equipotential level surfaces and are sufficiently general so as to include

A Cyclic Thermal Instability in Contact Binary Stars

It is shown analytically that contact binary stars coupled by a common convective envelope, the Lucy model, are almost invariably unstable when subjected to mass transfer: if either component begins


Sixty-one epochs of minimum light for 27 eclipsing binaries are presented. Where possible these epochs are compared to existing and reliable light elements. Improved light elements have been computed