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 report the discovery in $TESS$ Sectors 3 and 4 of a compact triplyeclipsing triple star system. TIC 209409435 is a previously unknown eclipsingbinary with a period of 5.717 days, and the presence of a third star in anouter eccentric orbit of 121.872 day period was found from two sets ofthird-body eclipses and from eclipse timing variations. The latter exhibitsignatures of strong 3rd-body perturbations. After the discovery, we obtainedfollow-up ground-based photometric observations of several binary eclipses aswell as another of the third-body eclipses. We carried out comprehensiveanalyses, including the simultaneous photodynamical modelling of $TESS$ andground-based lightcurves (including both archival WASP data, and our ownfollow-up measurements), as well as eclipse timing variation curves. Also, wehave included in the simultaneous fits multiple star spectral energydistribution data and theoretical PARSEC stellar isochrones. We find that theinner binary consists of near twin stars of mass 0.90 $M_\odot$ and radius 0.88$R_\odot$. The third star is just 9% more massive and 18% larger in radius. Theinner binary has a rather small eccentricity while the outer orbit has $e =0.40$. The inner binary and outer orbit have inclination angles within0.1$^\circ$ and 0.2$^\circ$ of 90$^\circ$, respectively. The mutual inclinationangle is $\lesssim 1/4^\circ$. All of these results were obtained withoutradial velocity observations.

The Compact Triply Eclipsing Triple Star TIC 209409435 Discovered with TESS