The new astronomical frontier: a stellar census to decipher planetary systems
As we approach the 2040s, planetary astronomy is undergoing a paradigm shift. Missions like Gaia, TESS, PLATO, and Nancy Grace Roman are detecting extrasolar worlds at an astonishing rate. However, the real challenge is no longer finding planets, but understanding them. The current bottleneck lies in deciphering how these distant systems are born, evolve, and diversify. The answer, according to experts, lies not only in the planets but in the stars that host them. 🔭
Connecting planets with the galaxy's history
To overcome this barrier, a massive spectroscopic census is needed. This project must analyze tens of thousands of stars, including both those with known planets and a control group without confirmed detections. Its scope must cover from the galactic disk to the halo, capturing the diversity of the Milky Way. The main goal is to measure homogeneous stellar parameters: detailed chemical composition, precise ages, and space motions. These data are key to linking a planet's properties with the galactic environment of its host star.
The fundamental pillars of the census:- Precise chemical abundances: Track the composition of the primordial material that formed each planetary system, measuring many distinct elements.
- Determine ages and kinematics: Reconstruct the dynamic history of each star and place it in the Galaxy's evolutionary timeline.
- Statistically robust population: Only with a large and uniform sample can theories be tested on how planets form in diverse environments, such as young clusters or the ancient halo.
The lack of a uniform and complete dataset currently limits progress. A dedicated project overcomes this barrier.
Answering questions that have no solution today
Currently, studies work with fragmented measurements from different sources, introducing systematic biases and making it difficult to reliably compare systems. A dedicated and homogeneous survey would allow addressing fundamental questions that remain unanswered today. For example, it could investigate whether the architecture of a planetary system (the number and type of planets) depends on the metallicity of its