The Final exam will be held on Friday, December 20, 2019, at 13.15-17.00 in L9.
Questions for the exam: [PDF]
765629S
Stellar Atmospheres
an advanced course (10 credits)
at the Astronomy research unit, University of Oulu
The course period: September 4 – December 20, 2019
Lectures, exercise and practical sessions take place usually on Wednesday at 14-16 and Friday at 12-14, see WebOODI for detail.
The course is lectured in English
Teacher: Vitaly Neustroev, MA 302, vitaly[-at-]neustroev.net
Course plan:
- Radiation terms and definitions
- Stellar photospheres
- Stellar atmospheres
- etc…
Theoretical and practical considerations will be supplemented with the home exercises which constitute the important part of the course.
Literature:
- Introduction to Stellar Astrophysics: Vol 2 – E. Böhm-Vitense
- Observations and analysis of stellar photospheres – D. F. Gray
- Lecture notes (not enough!)
Known typos and errors in the book by D. F. Gray
Schedule
- Lecture 1: September 4: Introduction (What is a stellar atmosphere? Spectral Types, Luminosity Classes, Magnitudes, Bolometric Flux and Bolometric Correction)
PDF - Lecture 2: September 6: Basics about radiative transfer (Radiation terms, Specific and mean intensity, Flux & luminosity, Black body radiation (Planck function), Effective temperature (Stefan-Boltzmann law), Brightness and Color temperatures)
PDF - Lecture 3: September 11: Basics about radiative transfer (radiation density and pressure), Interaction radiation – matter, Parallel-Ray transfer equation.
PDF - Lecture 4: September 13: Radiative transfer (Radiative transfer equation in plane-parallel atmosphere. Limb darkening), Solution to transfer equation, Eddington-Barbier relation. Grey atmosphere.
PDF - Lecture 5: September 18: Grey atmosphere. Radiative equilibrium. The depth dependence of the source function. Eddington approximation. Temperature structure of the grey atmosphere.
PDF - Lecture 6: September 20: LTE (Maxwellian distribution in velocities, Boltzmann equation, Saha formula).
PDF - Compulsory problems: [Set 1] (return by October 2).
- Lecture 7: October 2: Stellar Opacity (Bound-bound, bound-free and free-free absorptions).
PDF - Lecture 8: October 4: Other sources of opacity (H-, He and Metallic absorptions, Scattering, Effect of nongreyness of the temperature structure).
PDF - Lecture 9: October 9: Rosseland mean opacity, Towards the Model Photosphere (Hydrostatic equilibrium, Gas Pressure, Electron Pressure).
PDF - Lecture 10: October 11: Towards the Model Photosphere (Radiation pressure, Eddington limit).
PDF - Compulsory problems: [Set 2] (return by October 16 [Problem 3 is revised, return by October 30, 14:15]).
- Lecture 11: October 16: The Forgotten Chapters (Radiation, Astrophysical, and Eddington Flux; Wavelength dependence of absorption coefficients; Balmer jump).
PDF - Compulsory problems: [Set 3] (return by October 30, 14:15).
- Mid-term exam: October 30.
- Lecture 12: November 1: Spectral lines (Equivalent Width, FWHM, FWZI, Radial Velocity).
PDF - Practical Session: November 6: Software (Iraf, Dech).
Spectra of stars: Vega, Sun - Info Session: November 13.
Spectra of stars: Vega, Sun - Lecture 13: November 15: Spectral line formation (Einstein coefficients).
PDF - Lecture 14: November 22: Spectral line formation (Natural Line Width, Natural broadening, Doppler broadening, Pressure broadening).
PDF - Lecture 15: November 27: Spectral line formation (Pressure broadening, Convolution of different broadening processes, Ingis-Teller relation, Rotational and Instrumental broadening).
PDF - Lecture 16: November 29: Simple line transfer, Schuster-Schwarzschild model, Theory of line formation, Curve of Growth.
PDF - Lecture 17: December 11: Scattering in lines, Transfer Equation including lines, The Milne-Eddington model, Residual flux of the line, Absorption and scattering lines, Schuster Mechanism for Line Emission.
PDF - Lecture 18: December 13: non-LTE (Statistical equilibrium, Two-level approximation, the line source function, LTE versus non-LTE).
PDF - Lecture 19: December 18: Spectral type sequence. Measuring temperatures and surface gravities (Direct measurement of radii. Determining teff and surface gravity, Model-independent methods, Model-dependent methods, Atmospheric models, Photometric methods, Spectroscopic methods).
PDF * Spectral classification