skip to main content

Title: Asteroseismic estimate of helium abundance of a solar analog binary system

16 Cyg A and B are among the brightest stars observed by Kepler. What makes these stars more interesting is that they are solar analogs. 16 Cyg A and B exhibit solar-like oscillations. In this work we use oscillation frequencies obtained using 2.5 yr of Kepler data to determine the current helium abundance of these stars. For this we use the fact that the helium ionization zone leaves a signature on the oscillation frequencies and that this signature can be calibrated to determine the helium abundance of that layer. By calibrating the signature of the helium ionization zone against models of known helium abundance, the helium abundance in the envelope of 16 Cyg A is found to lie in the range of 0.231 to 0.251 and that of 16 Cyg B lies in the range of 0.218 to 0.266.
Authors:
;  [1] ; ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8]
  1. Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)
  2. Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)
  3. Astronomy Department, Yale University, P. O. Box 208101, New Haven, CT 065208101 (United States)
  4. Homi Bhabha Centre for Science Education, TIFR, V. N. Purav Marg, Mankhurd, Mumbai 400088 (India)
  5. Institut d'Astrophysique Spatiale, Université Paris XI-CNRS (UMR8617), Batiment 121, F-91405 Orsay Cedex (France)
  6. School of Physics and Astronomy, University of Birmingham, B15 2TT (United Kingdom)
  7. Laboratoire AIM, CEA/DSM, CNRS, Université Paris Diderot, IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette Cedex (France)
  8. Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark)
Publication Date:
OSTI Identifier:
22365455
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 790; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ELEMENT ABUNDANCE; HELIUM; IONIZATION; LAYERS; LEAVES; OSCILLATIONS; STARS; SUN