ASTROPHYSICS

This course deals with fundamental aspects of modern Astrophysics and gives the student the possibility of mastering them for the application to research, public outreach, and education in fields of the Science of the Universe. The lectures focus on the theory of the formation of stars and planetary systems, and stellar structure and evolution. They outline basic concepts and applications that have also wide implications for Galactic Astronomy and Cosmology.

Knowledge and understanding. The main goal of the course is to provide the student with a discriminating knowledge of stellar and planet formation mechanisms, of stellar structure and evolution from first principles. The acquisition of discriminating knowledge about the connections to related fields is also part of the course’s objectives.

Applying knowledge and understanding. The course allows the student to acquire skills in identifying the essential elements of astrophysical phenomena, in terms of order of magnitude and necessary approximation level, and in applying the necessary approximations. The student will also be capable of identifying the common theoretical framework amongst different areas and use analogy arguments to apply known solutions to new problems and different astrophysical contexts.

Making judgements. Students will gain the skills needed to compare observational data with theoretical models and plan experiments, if only at a conceptual level, aiming at revealing possible deviation from the models’ predictions.

Communication skills. The course gives the student the possibility of acquiring specific competences for a correct and effective communication of astrophysical topics.

Learning skills. The student can acquire adequate cognitive methods for a continuous update of Astrophysical subjects and the capability to access to the specialised literature in Astrophysical and related fields.

The main concepts are taught in front lectures, which include practical examples. Learning effectiveness is monitored through written exercises and intermediate tests.

Should the circumstances require online or blended teaching, appropriate modifications to what is hereby stated may be introduced, in order to achieve the main objectives of the course. Exams may take place online, depending on circumstances.

Attendance is compulsory according to the rules of the teaching regulations of the CdS in SFA as reported in the link:

http://www.dsf.unict.it/corsi/l-29_sfa/regolamento-didattico

STARS AND PLANETS FORMATION. Gravitational instability. Collapse of a spherical cloud. Contraction towards the main sequence. Characteristics of pre-main sequence stars. Accretion phenomena and formation of planetary systems.

STELLAR STRUCTURE AND EVOLUTION. Equations of stellar structure and their solution. Mass dependence of the stellar structure and evolution. Final stages of stellar evolution.

STELLAR OSCILLATION AND ASTEROSEISMOLOGY. Radial and non-radial oscillations of stars. Principles and applications of astroseismic models.

MAGNETIC STRUCTURE IN THE SOLAR ATMOSPHERE: Active regions, solar spots, prominences, loops, coronal holes. Emergence of magnetic flux in the solar atmosphere. Formation and evolution of active regions. The 11-year cycle of solar activity. The dynamo model. Chromospheric-coronal heating. Solar wind. Flares and filament eruptions. Coronal Mass Ejections.  Space Weather.

[1] Kippenhahn R., Weigert A., Weiss A., “Stellar Structure and Evolution”, 2nd edition, Springer-Verlag 2012

[2] T. Padmanabhan, “Theoretical Astrophysics”, Cambridge University Press, 2001

[3] Stahler S.W., Palla F., “The Formation of Stars”, Wiley-VCH, 2005

The following list is not exhaustive and represent only some examples

Discuss the gravitational instability of a isothermal spherical cloud

Discuss the differences in the evolution of low- and high-mass stars

What the Jeans' mass represents?

Discuss the time-scales of stellar evolution