Exoplanet atmosphere characterization:
from HST and Spitzer to JWST

A virtual meeting, March 9-12, 2021

About Exoplanets-A

Exoplanets-A is an European collaboration between CEA in France, CAB in Spain, MPIA in Germany,  UCL and Leicester University in UK, Universität Wien in Austria and SRON in the Netherlands . It is financed by the European Union´s Horizon 2020 research and innovation programme under grant agreement No GA 776403.

The goals are:

To establish new knowledge on the atmosphere of exoplanets by exploiting archived space data (HST, Spitzer, Kepler). More specifically, building on state-of the art knowledge and long term experience by the project team, novel data reduction methods based on causal pixel model will be developped and a homogeneous set of atmospheric exoplanet spectra from HST and Spitzer archives will be produced; ‘classical’ atmosphere parameters (atomic, molecular composition, pressure-temperature profile) retrieval approaches will be improved, making them able to simultaneously deal with transmission and emission observations and novel retrieval methods no longer based on a two steps approach (data reduction to get spectra and then retrieval from the spectra) will be developed, but on a one step approach combining data reduction and retrieval models; 3 D modelling of exoplanet atmosphere will be developed; the novel data reduction and retrieval tools will be used to analyse JWST observations of exoplanet atmospheres to be conducted in the framework of the JWST Early Release Science program.

To establish new insight on the influence of the star on the planet atmosphere. In particular archived space data (GAIA, XMM, Chandra, Herschel, IUE, HST), as well as complementary ground-based data, will be exploited to built a coherent and uniform database/catalogue of the properties of the host stars of the sample of exoplanets, and specifically those properties relating to the stellar activity which will influence the environment of the exoplanetary system (‘space weather’) and which are important in modelling and understanding the structure and evolution of the exoplanet’s atmosphere. The gaps in observational data, will be filled thanks to modelling tools and diagnostics to evaluate the star - planet interaction will be developed, especially in terms of tidal dissipation, magnetic field.

To disseminate knowledge, which consists of our science products, public outreach and educational resources. In particular a knowledge server connected to astronomical archives and virtual observatories will be produced and the scientific community and citizens will be engaged through contributive research and educational tools.

Aditional information, including access to data and tools, and outreach material, can be found at the Exoplanets-A webpage.