Theoretical Astrophysics

Physics, First Cycle
Educational Physics
3 year
Hours per week – 2. semester:
Content (Syllabus outline)

Review of main mechanisms in stellar astrophysics: introduction, connection with other areas of physics, basic properties of stars, timescales, hydrostatic equilibrium and virial theorem, production, transport and conservation of energy.
Properties of stellar matter: ideal gas, photon gas, description of a mixture of ideal gases and photon gas, degenerate matter, matter at high temperatures, ionization and Saha equation.
Equations of stellar structure: Derivation of equations of stellar structure. Hydrostatic equilibrium and polytropic stellar models: general properties of polytropic models and examples of their applicability, e.g., Chandrasekhar's mass. Thermodynamic equilibrium, local and global energy conservation, transfer of energy by radiation, convection and conduction, mass absorption coefficient, Rosseland mean. Examples of solving the equations of stellar structure in UV plane. Stability of stars.
Description of radiation field: equation of radiative transfer and some solutions. Optically thin and optically thick sources, black body radiation and energy transport in local thermodynamic equilibrium approximation, formation and properties of spectral lines in stellar atmospheres.
Nuclear reactions in stars: rate of nuclear reactions and nucleosynthesis in stars.
Stellar evolution: star formation and Jeans criterium, entrance on the main sequence of the Hertzsprung-Russell diagram and Hayashi line, main sequence description, helium ignition and post-main sequence evolution, end states of stars: compact stars and black holes.
High-energy astrophysics: supernovae explosions, gamma ray bursts, pulsars, plasma astrophysics, synchrotron radiation, particle acceleration, neutrinos and cosmic rays.


A.R. Choudhuri: Astrophysics for Physicists, Cambridge University Press 2010.
D. Prialnik: An Introduction to the Theory of Stellar Structure and Evolution, Cambridge University Press 2010.
R. Kippenhahn, A. Weigert: Stellar Structure and Evolution, Springer-Verlag 1994.
B.W. Carroll, D.A. Ostlie: Introduction to Modern Astrophysics, Addison-Wesley 1996.

Objectives and competences

Review and application of physical knowledge for description of stars and basic high-energy astrophysics.

Intended learning outcomes

Knowledge and understanding
Understanding of physical mechanisms responsible for formation, structure and observational properties of stars. Understanding of stellar stability, evolution, and end states.
Methods and results of stellar astrophysics are the basis for understanding of the Sun and stellar population in the Galaxy.
Reflection on modern knowledge about stars and the Universe, and about the importance of the Sun for us.
Transferable skills
Application of physical methods in description of stars. Modeling and importance of correct choice of key mechanisms and parameters for applicability and interpretation of a model.

Learning and teaching methods

Lectures, numerical problems, projects and consultations.


Mark from projects and colloquia/written exam
Mark from oral exam
Marks: 1-5 (negative), 6-10 (positive) according to UL Statute.

Lecturer's references

• PLANELLES, Susana, FABJAN, Dunja, BORGANI, Stefano, MURANTE, Giuseppe, RASIA, Elena, et al. Pressure of the hot gas in simulations of galaxy clusters. Monthly notices of the Royal Astronomical Society, ISSN 1365-2966, 2017, vol. 467, issue 4, str. 3827-3847
• PLANELLES, Susana, FABJAN, Dunja, et al. On the role of AGN feedback on the thermal and chemodynamicalproperties of the hot intracluster medium. Monthly notices of the royal astronomical society, ISSN 0035-8711, 2014, vol. 438, issue 1, str. 195-216
• FABJAN, Dunja, et al. X-ray mass proxies from hydrodynamic simulations of galaxy clusters – I. Monthly notices of the royal astronomical society, ISSN 0035-8711, 2011, vol. 416, issue 2, str. 801-816
• FABJAN, Dunja, et al. Simulating the effect of active galactic nuclei feedback on the metal enrichment of galaxy clusters. Monthly notices of the royal astronomical society, ISSN 0035-8711, 2010, vol. 401, issue 3, str. 1670-1690
• FABJAN, Dunja, et al. Evolution of the metal content of the intracluster medium with hydrodynamical simulations. Monthly notices of the royal astronomical society, ISSN 0035-8711, 2008, vol. 386, issue 3, str. 1265-1273