54973 - Stellar Evolution

Academic Year 2017/2018

  • Teaching Mode: Traditional lectures
  • Campus: Bologna
  • Corso: Second cycle degree programme (LM) in Astrophysics and cosmology (cod. 8018)

Learning outcomes

The aim of this course is to give a specialistic overview of the stellar evolution theory for stars with different masses.  In particular the student will understand how the main physical properties of stars with different masses change as a function of the age, how these changes are related to the thermonuclear evolution of each star, which are the final stages of star life, which are the properties of the remnants.

The student will also get a general view of the open issues in the field of the stellar evolution research.

Course contents

Pre-Main sequence evolution. Hayashi tracks. The core hydrogen-burning phase. The stellar structure along the Zero Age Main Sequence. Isothermal core properties and Shomberg-Chandrasekhar criterion. Post-Main sequence evolution. Envelope expansion. Sub-Giant and Red-Giant phases. The first Dredge-up. General properties of stars along the RGB: RGB-Bump and the development of a degenerate Helium core in low mass stars. The Helium flash. The Zero Age Horizontal Branch and the observational properties of the Horizontal Branch. Convection and the overshooting problem. The semi-convection theory. Double shell burning phase. The Asymptotic Giant Branch phase. The element production in the AGB. The second and third dredge-up. Pulsating stars. The period-luminosity relation. The k-mechanism and the partially ionized regions. Cepheids and RR Lyrae. The final stages of stellar evolution. White Dwarf properties. The Chandrashekar mass.  Type II and Ia Supernovae: progenitors, time scales, ejecta and remnants.

Readings/Bibliography

Lecture notes - Ferraro

An Introduction to modern Astrophysics - Carroll & Ostlie
Evolution of stars and stellar populations - Salaris & Cassisi
Astrofisica stellare - V. Castellani
Corso di Astrofisica - Cester
Astrophysics I. stars - Bowers& Deeming

Teaching methods

Lecures are presented by using power-point presentations

Assessment methods

The oral examination consists in a series of questions aimed at verifying that the student has a correct picture of the main evolutionary properties of low and high-mass stars.

Teaching tools

A pdf file with all the slides shown during lectures is available at the student web page.

Office hours

See the website of Francesco Rosario Ferraro