Asteroseismic estimate of helium abundance of a solar analog binary system

by Mr Kuldeep Verma (DAA-TIFR)

Tuesday 22 Apr 2014, 16:00 → 17:00 Asia/Kolkata

DAA Seminar Room A269 (Colaba Campus)

Helium is the second most abundant element in normal stars and has pronounced effect on their structure and evolution. Unfortunately, helium abundance cannot be determined spectroscopically for solar-like stars because of their low photospheric temperatures. A seismic study of such stars can provide an estimate of their envelope helium abundance. We use the fact that the helium ionization zone leaves a signature on oscillation frequencies and that this signature can be calibrated against the models of known helium abundance to determine the helium abundance of that layer. We use oscillation frequencies obtained using 2.5 years of Kepler data to determine the current helium abundance of a binary system, 16 Cyg A and B. These are solar-like stars and represent very closely the future of the Sun.