Asteroseismic estimate of helium abundance of a solar analog binary system

Journal Article · Fri Aug 01 00:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/790/2/138· OSTI ID:22365455

Verma, Kuldeep; Antia, H. M. ^[1]; Faria, João P.; Basu, Sarbani ^[2]; Mazumdar, Anwesh ^[3]; Appourchaux, Thierry ^[4]; Chaplin, William J. ^[5]; García, Rafael A. ^[6]; Metcalfe, Travis S. ^[7]

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1. Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)
2. Astronomy Department, Yale University, P. O. Box 208101, New Haven, CT 065208101 (United States)
3. Homi Bhabha Centre for Science Education, TIFR, V. N. Purav Marg, Mankhurd, Mumbai 400088 (India)
4. Institut d'Astrophysique Spatiale, Université Paris XI-CNRS (UMR8617), Batiment 121, F-91405 Orsay Cedex (France)
5. School of Physics and Astronomy, University of Birmingham, B15 2TT (United Kingdom)
6. Laboratoire AIM, CEA/DSM, CNRS, Université Paris Diderot, IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette Cedex (France)
7. Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark)

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.

• OSTI ID: 22365455
• Journal Information: Astrophysical Journal, Vol. 790, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ELEMENT ABUNDANCE
HELIUM
IONIZATION
LAYERS
LEAVES
OSCILLATIONS
STARS
SUN