TIC 278956474: Two close binaries in one young quadruple system, identified by \textit{TESS}

TL;DR

This paper reports the discovery and detailed analysis of a young quadruple star system with two close eclipsing binaries, using TESS data, spectroscopy, and other methods to constrain stellar properties and system age.

Contribution

The study presents the first detailed characterization of a young 2+2 quadruple system with two close eclipsing binaries identified by TESS, including mass, radius, and age estimations.

Findings

System is a young quadruple with two close eclipsing binaries.

Both binaries have observable primary and secondary eclipses.

System age estimated at 10-50 million years.

Abstract

We have identified a quadruple system with two close eclipsing binaries in TESS data. The object is unresolved in Gaia and appears as a single source at parallax 1.08~$\pm$0.01 mas. Both binaries have observable primary and secondary eclipses and were monitored throughout TESS Cycle 1 (sectors 1-13), falling within the TESS Continuous Viewing Zone. In one eclipsing binary (P = 5.488 d), the smaller star is completely occluded by the larger star during the secondary eclipse; in the other (P = 5.674 d) both eclipses are grazing. Using these data, spectroscopy, speckle photometry, SED analysis and evolutionary stellar tracks, we have constrained the masses and radii of the four stars in the two eclipsing binaries. The Li I EW indicates an age of 10-50 Myr and, with an outer period of $858^{+7}_{-5}$ days, our analysis indicates this is one of the most compact young 2+2 quadruple systems known.