Seismic Measurement of the Locations of the Base of Convection Zone and Helium Ionization Zone for Stars in the Kepler Seismic LEGACY Sample
- Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark)
- Homi Bhabha Centre for Science Education, TIFR, V. N. Purav Marg, Mankhurd, Mumbai 400088 (India)
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)
- Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 065208101 (United States)
Acoustic glitches are regions inside a star where the sound speed or its derivatives change abruptly. These leave a small characteristic oscillatory signature in the stellar oscillation frequencies. With the precision achieved by Kepler seismic data, it is now possible to extract these small amplitude oscillatory signatures, and infer the locations of the glitches. We perform glitch analysis for all the 66 stars in the Kepler seismic LEGACY sample to derive the locations of the base of the envelope convection zone (CZ) and the helium ionization zone. The signature from helium ionization zone is found to be robust for all stars in the sample, whereas the CZ signature is found to be weak and problematic, particularly for relatively massive stars with large errorbars on the oscillation frequencies. We demonstrate that the helium glitch signature can be used to constrain the properties of the helium ionization layers and the helium abundance.
- OSTI ID:
- 22661331
- Journal Information:
- Astrophysical Journal, Vol. 837, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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