Mergers prompted by dynamics in compact, multiple-star systems: a stellar-reduction case for the massive triple TIC 470710327

Abstract

TIC 470710327, a massive compact hierarchical triple-star system, was recently identified by NASA's Transiting Exoplanet Survey Satellite (TESS). TIC 470710327 is comprised of a compact (1.10 d) circular eclipsing binary, with total mass $\approx 10.9-13.2{\mathrm{M}}_{\odot }$, and a more massive ($\approx 14-17{\mathrm{M}}_{\odot }$) eccentric non-eclipsing tertiary in a $52.04$ d orbit. Here we present a progenitor scenario for TIC 470710327 in which '2+2' quadruple dynamics result in Zeipel-Lidov-Kozai (ZLK) resonances that lead to a contact phase of the more massive binary. In this scenario, the two binary systems should form in a very similar manner, and dynamics trigger the merger of the more massive binary either during late phases of star formation or several Myr after the zero-age main sequence (ZAMS), when the stars begin to expand. Any evidence that the tertiary is a highly-magnetised ($\sim 1-10$ kG), slowly-rotating blue main-sequence star would hint towards a quadruple origin. Finally, our scenario suggests that the population of inclined, compact multiple-stellar systems is reduced into co-planar systems, via mergers, late during star formation or early in the main sequence. The elucidation of the origin of TIC 470710327 is crucial in our understanding of multiple massive-star formation and evolution.

5 pages, 3 figures. Accepted for publication at MNRAS Letters

References in corpus (15)

• The surprising magnetic topology of tauSco: fossil remnant or dynamo output?
• How mergers magnetise massive stars
• The MiMeS survey of magnetism in massive stars: Magnetic analysis of the O-type stars
• Suppression of extreme orbital evolution in triple systems with short range forces
• On non-axisymmetric magnetic equilibria in stars
• Orbit alignment in triple stars
• Stellar mergers as the origin of the blue main-sequence band in young star clusters
• Long-term evolution of a magnetic massive merger product
• The effects of surface fossil magnetic fields on massive star evolution: I. Magnetic field evolution, mass-loss quenching and magnetic braking
• Secular chaotic dynamics in hierarchical quadruple systems, with applications to hot Jupiters in stellar binaries and triples
• Eccentricity and Spin-Orbit Misalignment in Short-Period Stellar Binaries as a Signpost of Hidden Tertiary Companions
• Six New Compact Triply Eclipsing Triples Found With TESS
• Chaotic quadruple secular evolution and the production of misaligned exomoons and Warm Jupiters in stellar multiples
• Planet Hunters TESS IV: A massive, compact hierarchical triple star system TIC 470710327
• The effects of surface fossil magnetic fields on massive star evolution: III. The case of $\tau$ Sco

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