Exploring Stellar Physics and Star-Planet Interaction through the Lens of stellar Chemical Abundance

Qinghui Sun (Tsinghua University)
Photometric and spectroscopic observations unveil important stellar properties, including chemical abundance, radial velocity, multiplicity, mass, distance, and age. Open clusters provide a homogeneous stellar sample with uniform age and similar metallicity, enabling systematic exploration of diverse stellar mechanisms. Lithium is destroyed in hot stellar interiors with an effective temperature exceeding 2.5 MK, while it can be produced in certain red giants and AGB stars. Thus, Lithium becomes pivotal in tracing internal stellar processes. Additionally, host stellar chemical compositions play a crucial role in shaping planetary systems. This talk explores the Lithium pattern in dwarfs, supporting the role of rotational mixing, and investigates the internal and external factors contributing to the formation of Lithium-rich giants. Furthermore, it discusses the correlation between the atmospheric abundance of planets and their host stars, and examines the planet engulfment signatures in stellar chemical abundances, especially Lithium.