Six new compact triply eclipsing triples found withTESS

Abstract

In this work we report the discovery and analysis of six new compact triply eclipsing triple star systems found with the TESS mission: TICs 37743815, 42565581, 54060695, 178010808, 242132789, and 456194776. All of these exhibit distinct third body eclipses where the inner eclipsing binary (EB) occults the third (‘tertiary’) star, or vice versa. We utilized the TESS photometry, archival photometric data, and available archival spectral energy distribution curves (SED) to solve for the properties of all three stars, as well as many of the orbital elements. We describe in detail our SED fits, search of the archival data for the outer orbital period, and the final global photodynamical analyses. From these analyses we find that all six systems are coplanar to within 0○ − 5○, and are viewed nearly edge on (i.e., within a couple of degrees). The outer orbital periods and eccentricities of the six systems are {Pout (days), e}: {68.7, 0.36}, {123, 0.16}, {60.7, 0.01}, {69.0, 0.29}, {41.5, 0.01}, {93.9, 0.29}, respectively, in the order the sources are listed above. The masses of all 12 EB stars were in the range of 0.7-1.8 M⊙ and were situated near the main sequence. By contrast, the masses and radii of the tertiary stars ranged from 1.5-2.3 M⊙ and 2.9-12 R⊙, respectively. We use this information to estimate the occurrence rate of compact flat triple systems.

The Visual Survey Group: A Decade of Hunting Exoplanets and Unusual Stellar Events with Space-Based Telescopes

“…We also check with team members of ground-based surveys to determine if there is any archival data for these sources (see e.g. Rappaport et al (2022) and references herein). There are a few members of the VSG-team who are expert in measuring the light centroid of the time varying part of the signal, and this is checked to be certain that the correct star has been identified.…”

The value-added catalogue of ASAS-SN eclipsing binaries: parameters of 30 000 detached systems

“…Photomometric and spectroscopic surveys have discovered tens of thousands of binary stars (Graczyk et al 2011;Prša et al 2011;Petrosky et al 2021;Pojmanski 2002;Jayasinghe et al 2019aJayasinghe et al , 2021Christy et al 2022;Pourbaix et al 2004). Interesting subsets of systems can then be identified from such large catalogs, such as extremely eccentric binaries (e.g., Zasche et al 2021), systems with changing eclipse depths (e.g., Davenport et al 2021), and triple and quadruple eclipsing systems (e.g., Rappaport et al 2022;Kostov et al 2022;Zasche et al 2022).…”

“…Tertiary companions can be identified in binary systems by monitoring the eclipse timing variations over timescales much longer than the orbital period (Borkovits et al 2015). Depending on the orbital inclination of the third body, they can also be discovered by detecting additional eclipses (Marsh et al 2014;Rappaport et al 2022). Similarly, quadruple systems made up of two pairs of eclipsing binaries can be found by searching for additional periods in the light curves of known eclipsing binaries (Kostov et al 2022;Zasche et al 2022).…”

TIC 114936199: A Quadruple Star System with a 12 Day Outer-orbit Eclipse

“…The Transiting Exoplanet Survey Satellite (TESS) mission (Ricker et al 2015) has allowed for the identification of many spectacular multiple-star systems through eclipses in the full frame image (FFI) light curves, for example, the near-perfectly coplanar and circular triple star system TIC 278825952, discovered by Mitnyan et al (2020), which contains an eclipsing binary (EB) that causes both eclipses and occultations of the tertiary star. Discoveries of many other interesting triply eclipsing triple star systems with TESS have been made by Borkovits et al (2020bBorkovits et al ( , 2022 and Rappaport et al (2022). The quadruple star system TIC 454140642 (Kostov et al 2021) is also of note as a compact and nearly coplanar system of two EBs consisting of similar-mass stars, coming within 1 au of each other during the course of their 432 day outer orbit.…”

“…Compact triple systems, defined here as having an outer-orbital period of less than a few years, are becoming more common with the advent of space-based photometric sky surveys such as CoRoT (Auvergne et al 2009), Kepler (Borucki et al 2010), and TESS. Perhaps the most fascinating of the compact triples are those that exhibit third-body eclipses (see, e.g., Borkovits et al 2016Borkovits et al , 2022Rappaport et al 2022). But, as eclipses and multistellar eclipsing systems become more well known and studied, we have noticed a glaring absence of quadruple star systems with outer-orbit eclipses, including among the many quadruples recently discovered by Kostov et al (2022) and Zasche et al (2022).…”