A Hunting Expedition For High-Order Hierarchies

Abstract

ABSTRACT Stellar hierarchical systems of high order containing more than three stars are rare and fascinating objects; their discovery and study highlight still unknown aspects of star formation and early evolution. We matched eclipsing binaries discovered by Transiting Exoplanet Survey Satellite with a Gaia catalogue of wide binaries and selected candidate quadruple (or higher order) systems based on excessive astrometric noise. A subset of 192 southern candidates located within 500 pc was observed by speckle interferometry, and we resolved for the first time 50 close pairs, confirming their high-order (from four to five components) multiplicity. These observations are reported, and some remarkable hierarchical systems are discussed.