27217 - Stellar Astrophyiscs

Learning outcomes

The aim of this course is to give a general overview of the set of equations that regulates the internal structure and the atmosphere of a star.  

Course contents

The lectures are articulated in two MODULES:

MODULE 1: the structure of stellar interiors and  stellar atmosphere; MODULE 2: resolving simple problems on stellar structure

MODULE 1

Structure of stars. Equation of stellar interiors. Hydrostatic equilibrium.The physical state of stellar matter. The degenerate matter. The LogT - Log(rho) diagram. The source of stellar energy. Thermonuclear reactions. The origin of chemical elements. Energy transport: radiation and convection. The Schwarzshild criterium. Sources of opacity in the stellar interiors. The Kramers equations.

The structure of the stellar atmosphere. Photon absorption and emission. Theory of the formation of spectral lines. Curve of growth and determination of chemical abundance in stars. Equation of Saha and Boltzmann. Basic stellar evolution.

MODULE 2

Definitiona and oeperative resolutions of simple exercizes aimed at deriving the main properties of a stellar strutures as radius, density, gravity, etc. 

Readings/Bibliography

The final exam can be prepared using the notes taken during the lessons and the Lecture Notes made available by the teacher every year at the site "Virtuale UniBO" of the Bologna University. Hence, the attending in person of the course is strongly recommended for a successful acquisition and understanding of the discussed topics. In addition, the attending student will have opportunity to ask questions during the lessons, for a full comprehension of the topics.

Additional textbooks useful for further deepening of specific topics are the following: 

(in italian)

Figli delle stelle - F.R. Ferraro

Astrofisica stellare - V. Castellani

Corso di Astrofisica - B. Cester

(in english)

An Introduction to modern Astrophysics - Carroll & Ostlie

Evolution of stars and stellar populations - Salaris & Cassisi

Astrophysics I. stars - Bowers& Deeming

Teaching methods

Lecures are presented by using power-point presentations.

Assessment methods

The exam consists of two parts.

The written test consists of 10 simple exercises dealing with the structure and the atmosphere of stars. The is based on the following scheme:

Grade A : very good. The student has resolved the majority (>8) exercises.

Grade B : good. The student has resolved a sufficient number (>5) of exercises, with some second-order computational errors. The student demonstrated that he/she is able to derive stellar structural quantities.

Grade C: not sufficient. The student has resolved only a few (<5) exercises, with some relevant computational errors. The student demonstrated that he/she is yet not able to derive stellar structural quantities.

During the test the student cannot use textbooks or notes but it is allowed the use of a small calculator.

The oral exam can be taken only if the evaluation of the written test is grade A or B. The written test is valid for one year. The final grade is based only on the oral test, that is aimed at verifying the student’s knowledge and understanding of the topics explained during the lessons, and their skills of organizing the answers (distinguishing the main, fundamental points from second-order details) and expressing them-selves using appropriate (scientific) language. It consists of 4-5 questions about the equations regulating the stellar structure and its atmosphere.

It typically lasts 40-45 minutes.

The final grade will be set based on the following scheme:

• grade=18-21: the knowledge is limited to just a small sub-sample of topics and the student answers to the questions only with a substantial help from the teacher
• grade=22-25: the knowledge concerns a larger number of topics, and the student answers the questions with some teacher help
• grade=26-28: the student is able to discuss most of the topics and answer the questions with good autonomy and critical sense, showing some uncertainties only on second-order points.
• grade=29-30L: the student shows solid and deep knowledge and excellent understanding of all the topics, answering to all questions readily and with very good mastery of the scientific terminology

During the exam, students are not allowed to use notes and books.

The student has the opportunity to refuse the assigned grade at most 2 times. Then, the last obtained grade (not the best one) will be registered.

Students with learning disabilities or temporary or permanent disabilities: please contact the relevant University office promptly (https://site.unibo.it/studenti-con-disabilita-e-dsa/en ). The office will advise students of possible adjustments, that will be submitted to the professor for approval 15 days in advance. He/she will evaluate their suitability also in relation to the academic objectives of the course.

  

Teaching tools

Lectures are performed with power-point presentations. The slides are updated and made available to the students every year on the dedicates web site "Virtuale uniBO" of the Bologna University

Office hours

See the website of Francesco Rosario Ferraro

See the website of Cristina Pallanca