Abstract Details
| Name: Satyajeet Moharana Affiliation: IISER Berhampur Conference ID: ASI2024_212 Title : Helium Abundance of the Sun: A Spectroscopic Analysis Authors and Co-Authors : Satyajeet Moharana1, Gajendra Pandey1, B.P. Hema1 Abstract Type : Poster Abstract Category : Stars, Interstellar Medium, and Astrochemistry in Milky Way Abstract : Determining the He/H ratio in cool stars presents a fundamental astrophysical challenge. While this ratio is established for hot O and B stars, its extrapolation to cool stars remains uncertain due to the absence of helium lines in their spectra. We address this knowledge gap by focusing on our Sun as a representative cool star. We employ spectroscopic analysis of the solar photosphere, utilizing MgH molecular and Mg I atomic lines alongside CH molecular and C I atomic lines to derive the photospheric He/H ratio. This ratio is determined by enforcing the fact that for an adopted model atmosphere with an appropriate He/H ratio, the derived Mg abundance from Mg I lines and that from the MgH lines of the MgH band, as well as the derived C abundance from C I lines and that from the CH lines of the CH band, must be the same. The estimated He/H ratio for the Sun is discussed based on the one-dimensional local thermodynamic equilibrium (1D LTE) model atmosphere. The results obtained for the Sun serve as a critical reference point for subsequent investigations aiming to characterize this ratio across a range of cool stars. |