96387 - STELLAR EVOLUTION

Conoscenze e abilità da conseguire

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.

Contenuti

Time scale of stellar evolution. Evolution tracks and isocrhrones. Jeans Mass. Pre-Main sequence evolution. Hayashi tracks. The core hydrogen-burning phase. The stellar structure along the Zero Age Main Sequence. Isothermal core properties and the 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.

Supernovae: Type II (core-collapse) and Ia (thermonuclear). Supernovae: progenitors, time scales, ejecta and remnants. Overview of the formation of the chemical elements in the Universe.

The structure of compact stellar remnants: Neutron stars (NS). Pulsar. Millisecond-Pulsar. Black Holes (BH). Gravitational waves (GW)- basic concepts – determination of the mass of the emitting system - GW from BH-BH and NS-NS systems – Kilonovae- explosive nucleosysnthesis and formation of heavy elements

Testi/Bibliografia

Lecture notes – Ferraro

Evolution of stars and stellar populations - Salaris & Cassisi

An Introduction to modern Astrophysics - Carroll & Ostlie

Astrophysics I. stars - Bowers & Deeming

Metodi didattici

Lecures are presented by using power-point presentations

Modalità di verifica e valutazione dell'apprendimento

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.

Strumenti a supporto della didattica

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

Orario di ricevimento

Consulta il sito web di Francesco Rosario Ferraro