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| SPAT0005-1 | Stellar stability and asteroseismology
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| Duration : | 30h Th, 10h Pr |
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| Credits/ECTS : |
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| Holder(s) : | Marc‑Antoine Dupret |
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| Language : | Langue française |
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| Course contents : | During their evolution, stars undergo phases of instability, which can manifest themselves violently, by a simple acceleration of their evolution, or by inducing a variability. The study of stellar variability leads to information about their internal structure. This is called asteroseismology. After the successes of helioseismology (same technique applied to the Sun), asteroseismology has now become a very popular subject, with several spatial missions planned in the near future. It is a unique tool to study the stellar interiors and the physical mechanisms at work inside the stars. It also leads to precise information about the global stellar parameters such as their mass, age, radius, chemical composition. |
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| Course objective : | Most of the following topics will be adressed and will have to be known.
* Position of a few types of variable stars in the HR diagram
* Stellar time scales
* Equations of hydrodynamics and thermodynamics
* Equilibrium configurations
* Small perturbations method
* Adiabatic perturbations
* Radial oscillations
* Adiabatic radial oscillations
* Asymptotic expression of radial frequencies
* Non radial oscillations
* Description of the non radial modes
* Influence of rotation
* Helio- and asteroseismology
* Non linear radial oscillations
* Basic techniques of asteroseismology on the main sequence of the HR diagram.
* Asteroseismic observations along the Main Sequence
* Modes in simple cavities
* Excitation mechanisms in stars
* Asteroseismology of solar type stars
* Asteroseismology of delta Scuti stars
* Asteroseismology of beta Cephei stars
* Determination of the frequencies
* Mode identification |
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| Prerequisites : | The student needs knowledge of mathematics and physics at the level of that taught at the level of bachelor in the physics section. Some knowledge of stellar structure and evolution will be useful. |
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| Organization : | 30 hours of lectures and 10 hours of practical lectures, some of these being for the preparation and presentation of the student's personal work. |
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| Written notes : | Lecture notes and powerpoint presentations will be made available to the students. |
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| Assessment : | The student will be evaluated on the basis of a personal work which will be proposed to him during the academic year. The student will have to present this work in front of the course lecturer, and maybe his peers and/or several scientists from the department of astrophysics and geophysics.
He will have to be able to answer oral questions on the content of the lectures as well as on his personnal work. A written report on his personnal work will be handed to the teacher several days before the oral presentation. |
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| Contacts : | Anne Thoul
Anne.Thoul@ulg.ac.be |
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