SOLAR PHYSICS

The objective of the course is to provide the students with the basic knowledge and the state of the art of several Solar Physics topics: knowledge of the methods used to investigate the solar interior and the solar atmosphere; knowledge of the mechanisms of interaction between the plasma and localised 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 magnetised plasma and the Earth magnetosphere in the framework of Space Weather; knowledge of methods used to analyse 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. Essential skills of the scientific method and understanding of the nature and 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 required approximation level. Ability to apply by analogy the solutions acquired in the solar physics field 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 their 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 their own research activity or a review topic both to an expert and to a 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 their knowledge and to access specialised literature both in the field of solar physics and in scientifically close fields. Ability to exploit databases, specific software and scientific resources to extract information and suggestions to better frame and develop their study and research activity. Ability to acquire, through individual study, knowledge in new scientific fields.

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

1. The solar interior: core, radiative zone, convective zone. The Standard Solar Model. Nuclear fusion in the solar core. Solar neutrino’s flux measurements. Helioseismology. Oscillations as a diagnostic tool to investigate the inner structure and dynamics of the Sun. The internal solar rotation.

2. The solar atmosphere: Photosphere, Chromosphere, Transition Region, Corona. 

3. Telescopes, Instruments and Techniques to observe the Sun: Techniques to observe the various layers of the solar atmosphere. Ground based and space-borne solar instrumentation. Spectroscopy (transport equation, spectral line formation, differential emission measure). Light polarisation. Spectropolarimetry. Space-borne spectrometers.

4. 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. Solar differential rotation. The dynamo model. Chromospheric-coronal heating. Solar wind. 

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

6. Tools and methods for solar data analysis: JHelioviewer. SolarSoftware (IDL). Sunpy (Python). Solar data archives. Analysis of solar images and magnetograms (SDO/AIA, SDO/HMI, Solar Orbiter/EUI, Solar Orbiter/PHI). Analysis of spectral data (Hinode/EIS, IRIS, Solar Orbiter/SPICE). Analysis of the solar corona (SoHO/LASCO, Solar Orbiter/Metis).  Magnetic field extrapolation (Magnetic Connectivity Tool).  

·       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

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

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

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 power point 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.