Astro Seminar: New insights into the Star-Planet Connection through Precision Spectroscopy

Stars and planets form from the same material, suggesting a possible chemical link between them. If this connection exists, we can study the composition of stars to learn about their planets and gain clues about their origins. The discovery of more than 5,800 exoplanets has revealed an astonishing diversity in planetary systems, highlighting the complexity of planet formation and making it challenging to confirm the star-planet connection.

Some of the strongest clues come from the Sun's chemistry, which seems depleted in refractory elements (those that form rocks) compared to solar twin stars. This may reflect the formation of rocky planets in our Solar System. Lithium is another interesting piece of the puzzle, and its depletion has been linked to planet formation, while unusually high lithium levels may suggest planet engulfment. Despite significant efforts over the past decade, the star-planet connection and the mechanisms behind lithium depletion or enhancement remain inconclusive.

In this talk, I will share my latest results on the star-planet connection, based on a sample of 200 planet-hosting stars. I will also present discoveries from the thick disk, where we have found several new exoplanets, adding to the small number of known planets around metal-poor stars, a population where planet formation is still not well understood.