SOLAR PHYSICS

The course is aimed at providing the student the basic knowledge and the state of the art of the knowledge in Solar Physics: knowledge of the methods used to investigate the solar interior and the solar atmosphere; knowledge of the mechanisms of interaction between the plasma and localized magnetic fields; concept of magnetic reconnection applied to transient phenomena taking place in the solar atmosphere; knowledge of the mechanisms of interaction between the solar magnetized plasma and the Earth magnetosphere in the framework of Space Weather; knowledge of methods used to analyze solar data.

Knowledge and understanding: Critical understanding of the most advanced developments in Modern Physics in both theoretical and laboratory aspects and of their interconnections, even in interdisciplinary fields. Adequate knowledge of advanced mathematical and computer tools of current use in the fields of basic and applied research. Considerable mastery of the scientific method, and understanding of the nature and of research methods in Physics. During the course the student will acquire the main concepts underlying the fundamental physical mechanisms that occur in the Sun.

Applying knowledge and understanding: Ability to identify the essential elements of a phenomenon (with reference to the phenomena occurring in the Sun), in terms of order of magnitude and level of approximation necessary, and to be able to make the required approximations. Ability to use the analogy tool to apply known solutions in the field of solar physics to new problems (problem solving) and different astrophysical contexts. Ability to use analytical and numerical mathematical calculation tools and computer technology, including the development of software programs (with specific reference to solar data analysis).

Making judgments: Ability to convey own interpretations of physical phenomena, when discussing within a research team. Development of sense of responsibility through the choice of optional courses and the subject of the master thesis.

Communication skills: Communication skills in Italian and English in the advanced fields of Physics. Ability to present one's own research activity or a review topic both to an expert and to an non-expert audience. These skills will be developed in the context of communicating the processes that take place in the Sun.

Learning skills: Ability to acquire adequate tools for the continuous update of one's knowledge and to access specialized literature both in the field of solar physics and in scientifically close fields. Ability to exploit databases, specific softwares and bibliographical and scientific resources to extract information and suggestions to better frame and develop one's study and research activity. Ability to acquire, through individual study, knowledge in new scientific fields.

The course is based on 35 hours of lectures (in English) and 15 hours of exercizes. The students will also be invited to attend (on-line) seminars on selected topics of solar physics. 

During the 15 hours devoted to exercizes some softwares (SolarSoftware e Sunpy), used by the scientific community to analyze solar data will be described. There will also be some guided visits to observational infrastructures of INAF - Catania Astrophysical Observatory.

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.

Necessary knowledge: Electromagnetism. Maxwell's laws. Lorentz force. Nuclear reactions. Theory of interaction radiation-matter. Law of induction of the magnetic field. Condition of frozen magnetic field. Magnetic reconnection.

 Attendance at the course is usually compulsory (see the Didactic Regulations of Course of Study).

The solar interior: core, radiative zone, convective zone. The Standard Solar Model. Nuclear fusion in the solar core. Measure of the solar neutrinos flux. Heliosismology. Oscillations as a diagnostic tool to investigate the inner structure and dynamics of the Sun. The internal solar rotation.

The solar atmosphere: Photosphere, Chromosphere, Transition Region, Corona. Solar differential rotation.

Telescopes, Instruments and Techniques to observe the Sun: Techniques of observation of the various layers of the solar atmosphere. Solar telescopes. Focal plane instruments. Polarization of light. Spectro-polarimetry.

Magnetic structures in the solar atmosphere: Active regions, sunspots, 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. 

Solar eruptive events: Flares and filament eruptions: observational characteristics and models. Coronal Mass Ejections.  Space Weather.

Tools and methods for solar data analysis: Jhelioviewer. SolarSoftware (IDL). Sunpy (Python). Data serach and retrieval: solar archives. Analysis of solar images and magnetograms (AIA, HMI). Analysis of spectral data (IRIS). YAFTA (Yet Another Feature Tracking Algorithm). Local Correlation Tracking. Magnetic field extrapolation. Sunspot models.

Textbooks:

• H. M. Antia, A. Bhatnagar, P Ulmschneider : Lectures on Solar Physics, Springer Verlag, 2003

• M. Aschwanden : Physics of the solar corona: an introduction, Springer, Praxis Pub. Ltd, 2004

• R. J. Bray, L. E. Cram, C. J. Durrant, R. E. Loughhead : Plasma loops in the solar corona, Cambridge University Press, 1991

• K. R. Lang : The Sun from Space, Springer, 2000

• E. Landi Degl'Innocenti : Fisica Solare, Springer Verlag, 2008

• E. R. Priest : Solar magnetohydrodynamics, Reidel Publ. Co., Dordrecht, 1984

• E. Tandberg-Hanssen, A. G. Emslie : The physics of solar flares, Cambridge University Press, 1988

Verification of learning will be carried out through an oral final exam. Through questions related to qualifying points of the various parts of the program, the exam is aimed at ascertaining the overall level of knowledge acquired by the candidate, his/her ability to critically address the topics studied and to correlate the various parts of the program.

Students may begin the exam with the exposition of a topic of their choice, based on the recommended texts and any review articles recommended by the lecturer and/or based on the discussion of results obtained through the application of the software illustrated during the course. The topic of their choice may be presented by means of a ppt presentation in order to assess expository and communication skills as well.

Exams may take place online, depending on circumstances.

The final grade will equally match the knowledge shown in the qualitative and quantitative arguments, the critical view of the topics dealt with during the course and the ability to correlate the various parts of the program.

The questions below are not an exhaustive list but represent only a few examples.

• Solar internal structure
  
• Solar Standard Model
  
• Helioseismology as a diagnostic tool to  investigate the solar interior
  
• Instruments for solar observation
  
• Solar activity phenomena and 11-years solar cycle
  
• Sunspots: physical and morphological characteristics
• Flares: physical and morphological characteristics
• Solar eruptive phenomena and Space Weather