Dice Question Streamline Icon: https://streamlinehq.com

Formation signatures in exoplanet atmospheric composition

Determine whether the composition of exoplanet upper atmospheres preserves information related to formation location—such as carbon-to-oxygen partitioning set by disk temperature and radius—and assess the impact of confounding formation and evolutionary processes on such inferences.

Information Square Streamline Icon: https://streamlinehq.com

Background

The author suggests that the partitioning of volatile elements between condensed and gaseous phases varies with disk temperature, potentially enabling formation-radius diagnostics via atmospheric compositions from transmission spectroscopy. However, multiple formation and evolutionary processes could obscure or erase these signals, making empirical validation essential.

References

Open questions and problems that I would like to see resolved include, in no particular order: Does the composition of the upper levels of exoplanet atmospheres retain formation information? The division of abundant elements such as carbon and oxygen between condensed and gaseous phases is expected to vary with temperature, and thus radius, in the disk. This opens up the possibility of using atmospheric composition measurements from transmission spectroscopy as a new probe of planet formation. Multiple confounding factors, in both planet formation and atmospheric evolution, might however frustrate such hopes.

— Planet formation theory: an overview (2412.11064 - Armitage, 15 Dec 2024) in Section “Some open questions”, Item 7