English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

KIC 2568888: To Be or Not to Be a Binary

MPS-Authors
/persons/resource/persons160261

Themeßl,  Nathalie
Max Planck Research Group in Stellar Ages and Galactic Evolution (SAGE), Max Planck Institute for Solar System Research, Max Planck Society;

/persons/resource/persons123110

Hekker,  Saskia
Max Planck Research Group in Stellar Ages and Galactic Evolution (SAGE), Max Planck Institute for Solar System Research, Max Planck Society;

/persons/resource/persons209280

Mints,  Alexey
Max Planck Research Group in Stellar Ages and Galactic Evolution (SAGE), Max Planck Institute for Solar System Research, Max Planck Society;

/persons/resource/persons220095

García Saravia Ortíz de Montellano,  Andrés
Max Planck Research Group in Stellar Ages and Galactic Evolution (SAGE), Max Planck Institute for Solar System Research, Max Planck Society;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Themeßl, N., Hekker, S., Mints, A., García, R. A., García Saravia Ortíz de Montellano, A., Stetson, P. B., et al. (2018). KIC 2568888: To Be or Not to Be a Binary. The Astrophysical Journal, 868(2): 103. doi:10.3847/1538-4357/aae846.


Cite as: http://hdl.handle.net/21.11116/0000-0003-7572-9
Abstract
In cases where both components of a binary system show oscillations, asteroseismology has been proposed as a method to identify the system. For KIC 2568888, observed with Kepler, we detect oscillation modes for two red giants in a single power-density spectrum. Through an asteroseismic study we investigate if the stars have similar properties, which could be an indication that they are physically bound into a binary system. While one star lies on the red giant branch (RGB), the other, more evolved star, is either a RGB or asymptotic giant branch star. We found similar ages for the red giants and a mass ratio close to 1. Based on these asteroseismic results, we propose KIC 2568888 as a rare candidate binary system (~0.1% chance). However, when combining the asteroseismic data with ground-based BVI photometry we estimated different distances for the stars, which we cross-checked with Gaia DR2. From Gaia we obtained for one object a distance between and broadly consistent with the distances from BVI photometry. For the other object we have a negative parallax with a not yet reliable Gaia distance solution. The derived distances challenge a binary interpretation and may either point to a triple system, which could explain the visible magnitudes, or, to a rare chance alignment (~0.05% chance based on stellar magnitudes). This probability would even be smaller, if calculated for close pairs of stars with a mass ratio close to unity in addition to similar magnitudes, which may indeed indicate that a binary scenario is more favorable.