Photometric analysis of overcontact binaries AK Her, HI Dra, V1128 Tau and V2612 Oph

Abstract

We analyze new, high quality multicolor light curves of four overcontact binaries: AK Her, HI Dra, V1128 Tau and V2612 Oph, and determine their orbital and physical parameters using the modeling program of G. Djurasevic and recently published results of radial velocity studies. The achieved precision in absolute masses is between 10 and 20%, and in absolute radii between 5 and 10%. All four systems are W UMa type binaries with bright or dark spots indicative of mass and energy transfer or surface activity. We estimate the distances and the ages of the systems using the luminosities computed through our analysis, and perform an O-C study for V1128 Tau, which reveals a complex period variation that can be interpreted in terms of mass loss/exchange and either the presence of the third body, or the magnetic activity on one of the components. We conclude that further observations of these systems are needed to deepen our understanding of their nature and variability.

arXiv comment32 pages, 5 figures, accepted for publication in AJ

References in corpus (11)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Validation of the new Hipparcos reduction
• A new calibration of stellar parameters of Galactic O stars
• Astrophysical parameters of Galactic open clusters
• Physical parameters of 62 eclipsing binary stars using the ASAS-3 data$-$I
• Radial Velocity Studies of Close Binary Stars. XI
• Radial Velocity Studies of Close Binary Stars. XII
• Origin of W UMa-type contact binaries - age and orbital evolution
• Radial Velocity Studies of Close Binary Stars.XIII
• Radial Velocity Studies of Close Binary Stars. XV
• The UNSW Extrasolar Planet Search: Methods and First Results from a Field Centred on NGC 6633

Cited by in corpus (11)

• Statistics of 700 individually studied W UMa stars
• Photometric study and absolute parameters estimation of six totally eclipsing contact binaries
• Catalogue and Properties of δ Scuti Stars in Binaries
• Investigation of the Orbital Period and Mass Relations for W UMa-type Contact Systems
• Physical parameters of close binary systems: VIII
• Starspots in contact and semi-detached binary systems
• The first photometric and spectroscopic analysis of the extremely low mass ratio contact binary NSVS 5029961
• A Photometric Study of Four Recently Discovered Contact Binaries: 1SWASP J064501.21+342154.9, 1SWASP J155822.10-025604.8, 1SWASP J212808.86+151622.0 and UCAC4 436-062932
• Light curve analysis of six totally eclipsing W UMa binaries
• Photometric and spectroscopic studies of the long period low mass ratio deep contact binary KN Per
• Long-term Spot Stability in the Post-common-envelope Binary QS Vir