The compact multiple system HIP 41431

T. Borkovits, J. Sperauskas, A. Tokovinin, D. W. Latham, I. Csányi, T. Hajdu, L. Molnár

Research output: Contribution to journalArticle

Abstract

The nearby (50 pc) K7V dwarf HIP 41431 (EPIC 212096658) is a compact three-tier hierarchy. Three K7V stars with similar masses, from 0.61 to 0.63 solar, make a triple-lined spectroscopic system where the inner binary with a period of 2.9 d is eclipsing, and the outer companion on a 59-d orbit exerts strong dynamical influence revealed by the eclipse time variation in the Kepler photometry. Moreover, the centre of mass of the triple system moves on a 3.9-yr orbit, modulating the proper motion. The mass of the fourth star is 0.35 solar. The Kepler and ground-based photometry and radial velocities from four different spectrographs are used to adjust the spectro-photodynamical model that accounts for dynamical interaction. The mutual inclination between the two inner orbits is 2- 16 ± 011, while the outer orbit is inclined to their common plane by 21°±16°. The inner orbit precesses under the influence of both outer orbits, causing observable variation of the eclipse depth. Moreover, the phase of the inner binary is strongly modulated with a 59-d period and its line of apsides precesses. The middle orbit with eccentricity e = 0.28 also precesses, causing the observed variation of its radial velocity curve. Masses and other parameters of stars in this unique hierarchy are determined. This system is dynamically stable and likely old.

Original languageEnglish
Article numberstz1510
Pages (from-to)4631-4647
Number of pages17
JournalMonthly Notices of the Royal Astronomical Society
Volume487
Issue number4
DOIs
Publication statusPublished - Jun 25 2019

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Keywords

  • binaries: Eclipsing
  • binaries: Spectroscopic
  • stars: Individual: HIP 41431

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Borkovits, T., Sperauskas, J., Tokovinin, A., Latham, D. W., Csányi, I., Hajdu, T., & Molnár, L. (2019). The compact multiple system HIP 41431. Monthly Notices of the Royal Astronomical Society, 487(4), 4631-4647. [stz1510]. https://doi.org/10.1093/mnras/stz1510