KOI-3890: a high-mass-ratio asteroseismic red giant+M-dwarf eclipsing binary undergoing heartbeat tidal interactions. Issue 1 (2nd May 2019)

• Record Type: Journal Article
• Authors: Kuszlewicz, James S; North, Thomas S H; Chaplin, William J; Bieryla, Allyson; Latham, David W; Miglio, Andrea; Bell, Keaton J; Davies, Guy R; Hekker, Saskia; Campante, Tiago L; Deheuvels, Sebastien; Lund, Mikkel N
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 487:Issue 1(2019)
• Page Start: 14
• Page End: 23
• Publication Date: 2019-05-02
• Subjects: asteroseismology -- techniques: photometric -- binaries: eclipsing -- stars: evolution -- stars: fundamental parameters; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stz1185
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: KOI-3890 is a highly eccentric, 153-d period eclipsing, single-lined spectroscopic binary system containing a red giant star showing solar-like oscillations alongside tidal interactions. The combination of transit photometry, radial velocity observations, and asteroseismology has enabled the detailed characterization of both the red giant primary and the M-dwarf companion, along with the tidal interaction and the geometry of the system. The stellar parameters of the red giant primary are determined through the use of asteroseismology and grid-based modelling to give a mass and radius of$M_{\star }=1.04\pm 0.06 \, \textrm{M}_{\odot }$ and$R_{\star }=5.8\pm 0.2 \, \textrm{R}_{\odot }$, respectively. When combined with transit photometry, the M-dwarf companion is found to have a mass and radius of$M_{\mathrm{c}}=0.23\pm 0.01 \, \textrm{M}_{\odot }$ and$R_{\mathrm{c}}=0.256\pm 0.007 \, \textrm{R}_{\odot }$ . Moreover, through asteroseismology we constrain the age of the system through the red giant primary to be$9.1^{+2.4}_{-1.7}\, \mathrm{Gyr}$ . This provides a constraint on the age of the M-dwarf secondary, which is difficult to do for other M-dwarf binary systems. In addition, the asteroseismic analysis yields an estimate of the inclination angle of the rotation axis of the red giant star of$i=87.6^{+2.4}_{-1.2}$ degrees. The obliquity of the system – the angle between the stellar rotation axis and the angle normal to the orbital plane – is also derived to give$\psi =4.2^{+2.1}_{-4.2}$ degrees, showing that the system is consistent with alignment. We observe no radius inflation in the M-dwarf companion when compared to current low-mass stellar models.