CoRoT Symposium 3, Kepler KASC-7 joint meeting
6-11 Jul 2014 Toulouse (France)
Asteroseismic estimate of helium abundance of 16 Cyg A,B
Kuldeep Verma  1@  , Joao Faria  2@  , H. M. Antia  1@  , Sarbani Basu  3@  , Anwesh Mazumdar  4@  , Mario Monteiro  2  , Thierry Appourchaux  5@  , William Chaplin  6@  , Rafael Garcia  7@  , Travis Metcalfe  8@  
1 : Tata Institute of Fundamental Research  (TIFR)  -  Website
Homi Bhabha Road, Mumbai 400005 - India -  India
2 : Centro de Astrofísica da Universidade do Porto  (CAUP)
3 : Department of Astronomy, Yale University  -  Website
260 Whitney Avenue, New Haven CT 06511 -  United States
4 : Homi Bhabha Centre for Science Education (TIFR)  (HBCSE)  -  Website
V. N. Purav Marg, Mumbai 400088 -  India
5 : Institut d'Astrophysique Spatiale - UMR8617  (IAS)
Université Paris XI - Paris Sud, Centre National de la Recherche Scientifique - CNRS
6 : School of Physics and Astronomy, University of Birmingham
Edgbaston, Birmingham B15 2TT, UK -  United Kingdom
7 : Laboratoire AIM, CEA / DSM – CNRS - Univ. Paris Diderot – IRFU / SAp, Centre de Saclay
Laboratoire AIM, CEA
8 : Space Science Institute  (SSI)  -  Website
SPACE SCIENCE INSTITUTE 4750 Walnut Street | Suite 205 Boulder, Colorado 80301 -  United States

16 Cyg A and B are among the brightest stars observed by Kepler. What makes these stars interesting is that they are solar analogs that exhibit solar-like oscillations. We use the oscillation frequencies of these stars obtained using 2.5 years of Kepler data to determine the current helium abundance in the envelopes of these stars. We use the oscillatory signal from the acoustic glitch due to HeII ionization zone for this purpose. The amplitude of the oscillatory signal is calibrated using stellar models with varying helium abundance to determine the helium abundance in these stars. The helium abundance in the envelope of 16 Cyg A is found to lie in the range 0.231 to 0.251 and that of 16 Cyg B lies in the range 0.218 to 0.266.


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