As part of preparations for ESA's PLATO mission, the public code for internal structure and stellar evolution Cesam2k20 has been selected to calculate the grid of first-generation stellar models (standard physics). The second-generation grid will need to include realistic chemical and angular momentum transport processes. The stellar evolution code that will be used to calculate this grid has not yet been chosen, but Cesam2k20 is among the candidates, given its track record in modeling transport mechanisms.

In order to strengthen the community around Cesam2k20, we are organizing a second edition of the Cesam2k20 workshop on November 13 and 14, 2025, for approximately 30 people, on the Triolet campus of the University of Montpellier.

This workshop will teach you how to:

• Install the Cesam2k20 code;
• Calculate a standard solar model;
• Explore the capabilities of Cesam2k20 for grid calculation;
• Use the associated optimization tools (AIMS, SPInS, OSM)

Cesam2k20 is the most recent version of the CESAM stellar evolution code.

The CESAM stellar evolution code was originally developed by Pierre Morel (1997, A&AS, 124, 597). More recent developments are presented in Morel & Lebreton (2008, ApSS 208, 316, 61-73). Bernard Pichon then participated in the development of a new version in modern Fortran: CESAM2k (Pichon, SF2A-2010: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics. Eds.: S. Boissier, M. Heydari-Malayeri, R. Samadi and D. Valls-Gabaud, p.271). Kinetic momentum transport was added by João P. C. Marques (Marques et al., 2013, A&A, 549A, 74M ) in the later version: CESTAM. Subsequent developments, the result of significant collaborative efforts, are included in the new version Cesam2k20.

We would like to extend our special thanks to SF2A, LUPM, UM, and AIPS, without whom the workshop would not be possible.

The Cesam2k20 logo was created by Ambre Réau.

The banner for this site was designed by Sylvain Cnudde (SIGAL, LIRA).

This workshop is free, as it is entirely funded by Paris-Observatory, through LUPM (Laboratoire Univers et Particules de Montpellier), SF2A (Socièté Française d'Astrophysique et Astronomie), UM (Université de Montpellier), and AIPS (Action Incitative de Physique Stellaire).

We can also provide financial assistance to certain participants who make a justified request. This financial support will probably not cover all you costs.

The workshop will follow the code of conduct established by the SF2A.

L. Manchon; Y. Lebreton; J. P. C. Marques; M. Deal; D. Lu; M. Vidal; J. Wang

SOC: L. Manchon; Y. Lebreton; J. P. C. Marques; M. Deal

LOC: M. Deal; A. Chennouf; L. Le Clainche; C. Mercier; J. Morin; E. Josselin; M. Vidal; J. Wang

and AIPS (Action Incitative en Physique Stellaire)