COMPASS

Compositions of Mini Planet Atmospheres for Statistical Study

Large JWST Cycle 1 GO program

Image from Gaillard & Scaillet (2014), showing different possible sources of small planet atmospheres. This is something our program will investigate — what do the atmospheric compositions of small planet tell us about their formation and evolution?

In November 2019, Natasha Batalha came to give a colloquium at Carnegie Observatories where I was postdoc. I told her about the Magellan-TESS Survey, and she wondered if we could extend that type of population-level framework to small planet atmospheres. Fast forward two and a half years and through many hours of wondering, working, and waiting, and we were awarded 141 hours of JWST/NIRSpec time to observe a subset of MTS targets to better understand the interaction between small planet interiors and atmospheres. Our program is the largest exoplanet allocation in Cycle 1 GO — 11 planets, + 1 from GTO observations will make a dozen planets total in our sample — and our data will have no proprietary period. The observations for our program are scheduled to begin in 2023, and I couldn’t be more excited to work with a fantastic, creative, diverse team to take this first step toward understanding small planet atmospheres as a population.

Stay tuned for more!