PřF:F8601 Model. of stellar atmospheres - Course Information

F8601 Modelling of stellar atmospheres

Extent and Intensity

2/1/0. 3 credit(s) (fasci plus compl plus > 4). Type of Completion: zk (examination).

Teacher(s)

doc. RNDr. Jiří Kubát, CSc. (lecturer)
Mgr. Brankica Kubátová, Ph.D. (lecturer)

Guaranteed by

doc. RNDr. Jiří Kubát, CSc.
Department of Theoretical Physics and Astrophysics – Physics Section – Faculty of Science
Contact Person: doc. RNDr. Jiří Kubát, CSc.
Supplier department: Department of Theoretical Physics and Astrophysics – Physics Section – Faculty of Science

Timetable

Tue 11:00–12:50 Fs1 6/1017, Tue 13:00–13:50 Fs1 6/1017

Prerequisites

Completion of the lecture F7600 "Physics of stellar atmospheres" is recommended.

Course Enrolment Limitations

The course is offered to students of any study field.

Course objectives

The goal is to offer a comprehensive view on procedures used in modeling stellar atmospheres and winds and on interrelationship of applied physical laws.

Learning outcomes

After completion of the course the students will:

be acquainted with the current state of knowledge of stellar atmospheres physics,

understand the interrelationships between the equations describing stellar atmospheres,

understand the current view of the formation of stellar winds,

be able to use modeling of stellar atmospheres and winds to analyze observations,

be able to continue their own study of the subject.

Syllabus

• Basic general equations of stellar atmospheres (radiative momentum and radiative energy, hydrodynamic equations a their simplification for one-dimensional atmospheres)
• Grey atmosphere (Hopf function, grey atmosphere with step opacity, backwarming, mean opacities (flux mean opacity, Rosseland mean opacity)
• One-dimensional hydrostatic model atmospheres (hydrostatic equilibrium, energy equilibrium (radiative equilibrium, convection), Unsöld-Lucy tempertaure correction method, convective instability criteria, modelling of convection, radiative transfer equation, equations for energy level populations, overview of necessary equations, discretization of equations and their solution, complete linearization method, application of the accelerated lambda iteration method, spherically symmetric model atmospheres, NLTE heating, radiative diffusion, stellar rotation, one-dimensional models of circumstellar disks)
• Opacity in model atmospheres (absorption, emission and scattering, line blanketing and its treatment in LTE and NLTE
• Stellar wind (types of stellar winds, pressure driven wind, isothermal stellar wind and its solution, effect of additional forces in stellar winds)
• Basic mechanisms of stellar-wind acceleration (coronal wind, wind driven by radiation)
• Dust driven wind (conditions, opacity, two-component description, momen- tum transfer between components)
• Line radiatively driven wind (mechanism of wind acceleration and momentum transfer, radiative acceleration, its determination and limiting cases, CAK solution and its properties, determination of terminal wind velocities and mass-loss rates, stability of stellar wind, inhomogeneous stellar wind)
• Multidimensional model atmospheres (basic overview)

Literature

recommended literature
• KUBÁT, Jiří. Základy fyziky hvězdných atmosfér, učební text
• HUBENÝ, Ivan and Dimitri MIHALAS. Theory of stellar atmospheres : an introduction to astrophysical non-equilibrium quantitative spectroscopic analysis. Princeton, N.J.: Princeton University Press, 2015, xvi, 923. ISBN 9780691163291. info
• LAMERS, Henny J. G. L. M. and Joseph P. CASSINELLI. Introduction to Stellar Winds. Cambridge University Press, 1999. ISBN 0-521-59565-7. info

Teaching methods

Lectures and excercises.

Assessment methods

Oral exam.

Language of instruction

English

Follow-Up Courses

• FA221 Open problems of physics of stellar atmospheres and winds

Further Comments

Study Materials
The course is taught annually.

• Enrolment Statistics (Spring 2023, recent)
  
• Permalink: https://is.muni.cz/course/sci/spring2023/F8601