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 use photometric and spectroscopic observations of the eclipsing binariesV65, V66 and V69 in the field of the globular cluster M4 to derive masses,radii, and luminosities of their components. The orbital periods of thesesystems are 2.29, 8.11 and 48.19 d, respectively. The measured masses of theprimary and secondary components (Mp and Ms) are 0.8035+-0.0086 and0.6050+-0.0044 Msun for V65, 0.7842+-0.0045 and 0.7443+-0.0042 Msun for V66,and 0.7665+-0.0053 and 0.7278+-0.0048 Msun for V69. The measured radii (Rp andRs) are 1.147+_0.010 and 0.6110+-0.0092 Rsun for V66, 0.9347+_0.0048 and0.8298+-0.0053 Rsun for V66, and 0.8655+-0.0097 and 0.8074+-0.0080 Rsun forV69. The orbits of V65 and V66 are circular, whereas that of V69 has aneccentricity of 0.38. Based on systemic velocities and relative proper motions,we show that all the three systems are members of the cluster. We find that thedistance to M4 is 1.82+-0.04 kpc - in good agreement with recent estimatesbased on entirely different methods. We compare the absolute parameters of V66and V69 with two sets of theoretical isochrones in mass-radius andmass-luminosity diagrams, and for an assumed [Fe/H] = -1.20, [alpha/Fe] = 0.4,and Y = 0.25 we find the most probable age of M4 to be between 11.2 and 11.3Gyr. CMD-fitting with the same parameters yields an age close to, or slightlyin excess of, 12 Gyr. However, considering the sources of uncertainty involvedin CMD fitting, these two methods of age determination are not discrepant. Ageand distance determinations can be further improved when infrared eclipsephotometry is obtained.

The cluster ages experiment (CASE). V. Analysis of three eclipsing binaries in the globular cluster M4