Summary

One year before the launch of the PLATO mission, we believe it is timely to prepare the French community for the exploitation of these data to ensure the stellar physics spin-offs of this mission, to which France is strongly committed.
The aim of this school is to show how PLATO will enable remarkable advances in the physics of exoplanetary systems, not only by detecting and characterizing planets, but also by precisely characterizing stars through the determination of their fundamental parameters (mass, radius), their age, their internal structure or their magnetic activity. We’ll also show how PLATO’s seismology will enhance our understanding of stellar evolution and constrain internal processes.
With this school, we propose to mobilize the French community to prepare it for the exploitation of the data that the satellite will provide one year later. France is one of the main contributors to this ESA mission, with major contributions from Paris Observatory, INSU and CNES. It is therefore essential to prepare the community so that it is in a position to make the best possible use of the data and obtain a scientific return commensurate with the human and financial commitments invested by France in the project. This requires a major training effort, both in terms of scientific issues and data use.

Scientific justification

The PLATO (PLAnetary Transits and Oscillations of Stars, Rauer et al. 2024) space mission, adopted in June 2017 as the 3rd medium-class mission in ESA’s Cosmic Vision program, is scheduled for launch at the end of 2026. Its scientific objective is the study of planetary systems: its originality lies in the fact that, for the first time, the instrument will enable the joint study of a star and its procession of planets. To achieve this, it combines two cutting-edge approaches: the detection of exoplanets using the transit method, and the study of the internal structure of stars using stellar seismology, i.e. the study of stellar oscillations. This will be made possible by ultra-high-precision photometric tracking of several hundred thousand target stars continuously over several years. PLATO will be the first space photometry mission to enable both long-term photometric tracking (unlike TESS) of bright stars (unlike CoRoT, Kepler and K2). This feature will enable complementary observations from the ground, in particular through spectroscopy. Seismic analyses can provide precise determinations of stellar properties (mass, radius and age, for example), as well as constraining and improving our models of stellar evolution (in particular their internal dynamics and the transport processes taking place within them). In addition to seismology, stellar light curves can also be used to measure the level of magnetic activity and the rate of rotation, key elements for characterizing stellar magnetic fields and better understanding their generation by dynamo phenomena, and their interactions with exoplanets, in particular their habitability. A year before the mission’s launch, we feel it’s time to prepare the French community for the exploitation of these data to ensure the stellar physics spin-offs of this mission, to which France is strongly committed.
The aim of this school is to show how PLATO will enable remarkable advances in the physics of exoplanetary systems, not only by detecting and characterizing planets, but also by precisely characterizing stars through the determination of their fundamental parameters (mass, radius), age, internal structure or magnetic activity. We’ll also show how PLATO’s seismology will enhance our understanding of stellar evolution and constrain internal processes.
With this school, we propose to mobilize the French community to prepare it for the exploitation of the data that the satellite will provide one year later. France is one of the main contributors to this ESA mission, with INSU and CNES making major contributions. It is therefore essential to prepare the community so that it is in a position to make the best possible use of the data and obtain a scientific return commensurate with the human and financial commitments invested by France in the project. This requires a major training effort, both in terms of scientific issues and data use.
To this end, the school we are proposing will train researchers, doctoral students and post-doctoral fellows in the scientific themes in which the mission will enable the most decisive advances. This is why the school will be structured around stellar seismology, stellar activity and stellar rotation. In addition, the emphasis will be on synergies between different communities on thematic aspects around galactic archaeology or exoplanetology, but also on methodological aspects with complementary observational approaches (spectroscopy, spectropolarimetry, astrometry, interferometry).
In addition, practical issues linked to the arrival of the data will be addressed, so that the French community, and the younger generation in particular, are best equipped to exploit the data quickly and efficiently. Indeed, the data that will be made available to the community is by its very nature complex, as it is the result of numerous processing operations designed to extract high-level products that can therefore be rapidly exploited. It is therefore essential to provide all the tools and expertise needed to understand them in the best possible way. The school will therefore provide an opportunity, through practical work, to introduce the community to the data that will be accessible, as well as the tools they will need to master. In particular, the school will be an opportunity for the French community to learn how to use future PLATO data, by training on simulated data that is as realistic as possible. To this end, we plan to have the practical work defined and implemented by speakers who are involved in the development of the mission’s data processing chains.

This will be the first PLATO school to be organized in France. The need to set up mission-related schools has been particularly emphasized by the mission consortium. Exploitation of the mission’s data will be based on the expertise acquired through past and current missions (in particular CoRoT, Kepler and TESS), but it will also have its own specific features for which it is important to prepare the French community to ensure scientific spin-offs.
The proposed theme, although focused on stellar physics, presents a strong interface with the exoplanet theme, since, as described above, the PLATO mission will cover both fields. There is also a strong synergy with galactic physics via galactic archaeology. The research themes addressed by the school (seismology, stellar activity, exoplanets, galactic archaeology, etc.) are extremely active today, thanks to the current exploitation of existing data, in particular from the Kepler mission, and new data, in particular from TESS. The arrival of PLATO will accelerate this dynamic.
In this final phase of mission preparation, it’s important to provide the French community with the tools they need to make the most of the mission’s data. The “school” format provides an overview of the major questions and issues associated with PLATO, giving the physical foundations needed to understand the phenomena and observations involved. The school format also gives participants a better understanding of the nature and specificities of PLATO data and the associated analysis and interpretation tools.

The proposed school follows in the footsteps of the prestigious Écoles Evry Schatzman, held annually since 1989: https://www.pnps.cnrs.fr/ees.html. The idea of an annual stellar physics school was launched in 1989 by Evry Schatzman and Annie Baglin, then heads of the GDR Structure Interne des Étoiles et des Planètes Géantes. Since 2000, the annual theme has been selected by the PNPS Scientific Council, on the basis of proposals made by the PNPS community. Starting with the 2009 edition, the PNPS Scientific Council has decided to rename the school the “Evry Schatzman School”, in honor of its founder. The school usually attracts between 35 and 50 participants, both emerging and established researchers.
The school is aimed primarily at researchers, PhD students and post-docs working on the subject in question, and wishing to develop projects linked to the scientific exploitation of PLATO, but also at PhD students, post-docs and researchers wishing to discover and learn about the stellar physics accessible with PLATO. The school is aimed at current and potential players who will be called upon to analyze, exploit and interpret PLATO data.

The site is under construction and its address is https://ees2025.sciencesconf.org

Preliminary program

Monday 22/09 :
Morning :
– PLATO presentation - 1h (MJ Goupil)
– "Seismology" course (I - theory) - 2h (J. Philidet)
Afternoon :
– "Seismology" course (II - data analysis) - 2h (RA García)
– “Seismology” practical session - 2h (RA García)

Tuesday 09/23:
Morning:
– "Activity and rotation" course (I - theory) - 1h30 (S. Breton)
– "Activity and rotation" course (II - observations, exoplanet link) - 1h30 (S. Breton, participation by G. Bruno)
Afternoon :
– "Activity and rotation" practical session - 2h (S. Breton)

Wednesday 24/09:
Morning :
– “Seismic Inferences” course (I - general principles) - 1h30 (G. Buldgen)
– "Seismic Inferences" course (II - non-standard processes) - 1h30 (G. Buldgen)
Free afternoon then
– seminar “Exoplanets” - 1h (M. Deleuil)

Thursday 09/25:
Morning :
– "Seismology" course (III - classical pulsators) - 1h30 (J. Philidet)
– "Classical parameters" course - 2h (M. Bergemann)
Afternoon:
– “Seismic Inferences” practical session- 2x1h30 (G. Buldgen, participation M. Deal)

Friday 26/09:
Morning:
– "Galactic archaeology" course (I - standard methods) - 1h30 (A. Miglio)
– "Galactic archaeology" course (II - contribution of seismology) - 1h30 (A. Miglio)
Classes end after lunch.