Prof. O. Creevey, V. Parmentier
(S2, elective, 3 ECTS)
|Exoplanets are new windows into our Universe. We want to know what they are made of, how they were formed and ultimately whether they may harbor life. Characterizing exoplanets i.e., measuring their physical parameters and atmospheric properties to infer their structure and composition is key. They are part of systems including one or several stars and therefore the combined evolution of stars and planets is essential to learn more about these objects. We propose a course that combines expertise on stellar and planetary atmospheres, structure and evolution with the goal to characterize exoplanets and their parent stars.
|Knowledge and Understanding:
|The students will learn the physical principles behind the internal structure, atmosphere and evolution of stars and planets. Both Standard and modern concepts will be presented.
Theoretical and numerical approaches are proposed : The first part will be dedicated to the derivation of the fundamental equations and the understanding of the general concepts in the fields of stellar physics and planetology. With this background, the students will have the opportunity to use state-of-the-art numerical codes based on these principles to approach current hot topic problems in exoplanetology and interpret recent observed data.
|Applying Knowledge and Understanding:
|Hands-on course: The students will learn how to use the stellar evolution code CESAM, which allows one to predict the physical parameters as a function of input mass, composition, age. They will calculate evolution tracks for the Sun and test how these models change when different physical inputs are used.
The students will also learn to use a radiative/convective equilibrium code
scCHIMERA that can calculate the thermal profile and the spectra of an atmosphere. They will first study the effect of different parameters, such as
the chemistry, the gravity or the irradiation on the thermal profile and spectral properties of the atmosphere. Then they will perform an individual
project based on interpreting the emission and transmission spectra of recent JWST observations of exoplanets.
|Basics of stellar evolution (O.Creevey).
Stellar Evolution: Main Equations of radiative hydrostatic equilibrium, energy transport, equations of state (EOS), opacities to understand the HR diagram. Topics on determining planet-host parameters (radius, mass, age). Exploration of the properties with age. Discussions on impact of Limb Darkening and stellar cycles for the detection and characterization of transiting exoplanets.
Basics of planet evolution (V. Parmentier):
Mass radius diagram for solid and gaseous planets. Importance of equation of state. Thermal evolution of gaseous planets. Atmospheric boundary conditions. Role of stellar irradiation. Inflated exoplanet problem and solutions.
Basics of exoplanet atmospheres (V. Parmentier) :
Equilibrium temperature. Radiative/convective equilibrium. Atmospheric chemistry. Molecular opacities. Atmospheric dynamics. Formation of
emission and transmission spectra. Observations of exoplanet atmospheres. Parameter inferences from low and high spectral resolution observations.
|Description of how the course is conducted
|Powerpoints, lectures, articles, analytical and hands-on exercises
|Description of the didactic methods
|Lectures, exercises and project work
|Description of the evaluation methods
|• Written exam on the theoretical lectures
• Homework evaluation
• Oral presentation of articles
• Mini project work
|Stellar astrophysics (Leblanc)
Lecture notes in stellar evolution (Christiansen-Dalsgaard)