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 present the most comprehensive analysis to date of the Upper CentaurusLupus eclipsing binary MML 53 (2.097892 d), and for the first time, confirm thebound-nature of the third star (~9yr orbit). Our analysis uses new and archivalspectra and time-series photometry. We determined the temperature of theprimary star to be 4880+-100 K. The study of the close binary incorporatedtreatment of spots and dilution by the tertiary in the light curves, allowingfor the robust measurement of the masses of the eclipsing components within 1%(M1=1.0400+-0.0067 and M2=0.8907+-0.0058 Msun), their radii within 4.5%(R1=1.283+-0.043 and R2=1.107+-0.049 Rsun), and the secondary temperature(4379+-100K). From the analysis of the eclipse timings, and the change insystemic velocity of the eclipsing binary and the radial velocities of thethird star, we measured the mass of the outer companion to be 0.7 Msun within20%. The age we derived from the evolution of the temperature ratio between theeclipsing components is fully consistent with previous estimates of the age ofUCL (16+-2 Myr). At this age, the tightening of the MML 53 eclipsing binary hasalready occurred, thus supporting close-binary formation mechanisms that actearly in their evolution. The eclipsing stars roughly follow the sametheoretical isochrone, but appear to be inflated in radius (by 20% for theprimary and 10% for the secondary). However, our primary radius measurement ofis in full agreement with the independent measurement of the secondary of NPPer which has the same mass and a similar age. The eclipsing stars of MML 53are found to be larger but not cooler than predicted by non-magnetic models, itis not clear what is the mechanism that is causing the radius inflation giventhat activity, spots and/or magnetic fields slowing their contraction, requirethe inflated stars to be cooler to remain in thermal equilibrium.

Fundamental properties of the pre-main sequence eclipsing stars of MML 53 and the mass of the tertiary