English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We present photometric observations in Sloan filters g', i' of the eclipsingW UMa stars USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac. Thesinusoidal-like O-C diagram of V471 Cas shows presence of third body with massof 0.12 Msun (red dwarf) at distance 897 Rsun. The O-C diagram of V479 Lacreveals period decreasing. The results of the light curve solutions are: (i)The targets are overcontact binaries with small fill-out factors; (ii) Theircomponents are F-K stars, comparable in size, whose temperature differences arebelow 80 K; (iii) All targets undergo partial eclipses and to limit thepossible mass ratios we carried out two-step $q$-search analysis. The targetglobal parameters (luminosities, radii, masses) were obtained on the base oftheir GAIA distances and the results of our light curve solutions. The obtainedtotal mass of V560 Lac turns out smaller than the lower mass limit for thepresently existing W UMa binaries of 1.0-1.2 Msun, i.e. this target is anpeculiar overcontact system.

The W UMa binaries USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac: light curve solutions and global parameters based on the GAIA distances