Planet formation in inner disks enters the observational era – CHAIN

The past decades have witnessed a revolution in planetary science, showing the ubiquitousness of planets around other stars and the striking diversity in their properties. Understanding the origin of this diversity and the routes to the emergence of habitable planets is one of the holy grails of astrophysics and a persistent question of mankind.

Tremendous progress has been made in planet formation studies thanks to millimeter observations, which unveil the outer disks ( 20 AU). Yet, the majority of planets, notably in the Solar System, formed in the inner regions best traced by infrared wavelengths. Today, planet formation theory is maturing, but it critically misses an anchor point in the observations.

With the launch of the James Webb Space Telescope (JWST), the planet-forming regions in disks are now within our reach. Initiating a harvest of results, the first spectra published by myself and my collaborators show an astonishing diversity with spectacular emission lines tracing the chemical and physical structure of these poorly known regions. Yet, inner disks are optically thick and dynamic environments that require a new generation of models to exploit the JWST data.

Building on my complementary expertise in dynamics and chemistry and my unique access to several major JWST programs, I will lead the analysis of large samples of JWST data. We will obtain ground-breaking results by developing a novel model coupling dynamics, chemistry, and radiative transfer. With this strategic asset, we will uniquely address fundamental questions in planet formation by (1) measuring the inflow rate of pebbles, which sets the growth rate of planetary embryos, (2) estimating the elemental ratios in the gas, essential to interpret exoplanet atmospheric composition, and (3) characterizing the disk winds, vital for realistic planet formation models. All together, this program will unlock the promise of JWST by bringing planet formation theory in inner disks to the realm of observations.