Abstract Details
| Name: Anohita Mallick Affiliation: Indian Institute Of Astrophysics Conference ID: ASI2024_736 Title : Exploring the Interplay of Lithium and Chromospheric Helium in Red Giants: A Kepler and TESS mission study Authors and Co-Authors : Anohita Mallick1,2, Christopher Sneden3, Melike Afşar3,4, Bacham E. Reddy1 Abstract Type : Poster Abstract Category : Stars, Interstellar Medium, and Astrochemistry in Milky Way Abstract : NASA's Kepler and TESS missions have facilitated a comprehensive investigation into red giant asteroseismology. We have analyzed a dataset comprising 65 Kepler red giants, each with Lithium abundances obtained from literature sources or directly measured from LAMOST medium-resolution spectra and displaying detectable solar-like oscillations in their light curves. Using high-resolution spectra (R ~ 55,000) from the Habitable Zone Planet Finder (HPF) spectrograph on the 10m Hobby Eberly Telescope HET, we acquired near-infrared observations of the He I λ10830 Å absorption line. We have discussed how strength of the He I λ10830 Å line is closely associated with chromospheric disturbances resulting from post-helium flash shock waves, as well as fluctuations in chromospheric temperature and densities. In addition, we have extracted global asteroseismic parameters for all sample giants to assign accurate seismic evolutionary status. We also measured seismic masses of the stars and considered the effects of binarity and infrared excess on the strength of the He I λ10830 Å line. This work is first of its kind to establish a clear relationship between lithium abundance and chromospheric helium of red giants and core He-burning stars. |