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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We used the newly commissioned 50 cm Binocular Network (50BiN) telescope atQinghai Station of Purple Mountain Observatory (Chinese Academy of Sciences) toobserve the old open cluster NGC 188 in V and R as part of a search forvariable objects. Our time-series data span a total of 36 days. Radial velocityand proper-motion selection resulted in a sample of 532 genuine clustermembers. Isochrone fitting was applied to the cleaned cluster sequence,yielding a distance modulus of (m - M)0V = 11.35 \pm 0.10 mag and a totalforeground reddening of E(V - R) = 0.062 \pm 0.002 mag. Light-curve solutionswere obtained for eight W Ursae Majoris eclipsing-binary systems (W UMas) andtheir orbital parameters were estimated. Using the latter parameters, weestimate a distance to the W UMas which is independent of the host cluster'sphysical properties. Based on combined fits to six of the W UMas (EP Cep, EQCep, ES Cep, V369 Cep, and--for the first time--V370 Cep and V782 Cep), weobtain an average distance modulus of (m - M)0V = 11.31 \pm 0.08 mag, which iscomparable with that resulting from our isochrone fits. These six W UMasexhibit an obvious period-luminosity relation. We derive more accurate physicalparameters for the W UMa systems and discuss their initial masses and ages. Theformer show that these W UMa systems have likely undergone angular-momentumevolution within a convective envelope (W-type evolution). The ages of the WUMa systems agree well with the cluster's age.

Physical parameter study of eight W Ursae Majoris-type contact binaries in NGC 188