University of St Andrews

Key information

SCOTCAT credits : 15

ECTS credits : 7

Level : SCQF level 11

Semester: 2

Availability restrictions: Available only to students on MSc Astrophysics.

Planned timetable: 12 noon odd Mon, 3.00 pm even Tue, 12 noon Wed & Fri

This module develops the physics of stellar interiors and atmospheres from the basic equations of stellar structure and radiative transfer concepts developed in Nebulae and Stars I. Topics include: the equation of state that provides pressure support at the high temperatures and densities found in normal and white-dwarf stars; the interaction of radiation with matter, both in terms of radiation-pressure support in super-massive stars and in terms of the role of opacity in controlling the flow of energy from the stellar interior to the surface; the equation of radiative transfer and the effects of local temperatures, pressures and velocity fields on the continuum and line absorption profiles in the emergent spectrum. Computer-aided tutorial exercises illustrate the computational schemes that represent one of the triumphs of late twentieth-century physics, in their ability to predict the observable properties of a star from its radius and luminosity, which in turn are determined by its mass, age and chemical composition.

Relationship to other modules

Pre-requisite(s): Students must be registered for MSc Astrophysics.. Before taking this module you must pass AS4011 or equivalent from first degree.

Co-requisite(s): You must also take AS5500

Learning and teaching methods and delivery

Weekly contact: 3-hours of lectures (x 11 weeks), 1-hour tutorials (x 5 weeks)

Scheduled learning hours: 38

Guided independent study hours: 112

Assessment pattern

As used by St Andrews: 2-hour Written Examination = 75%, Coursework = 25%

As defined by QAA
Written examinations : 75%
Practical examinations : 0%
Coursework: 25%

Personnel

Module coordinator: Dr P Woitke
Module teaching staff: Dr P Woitke

Additional information from school

Develop a deeper understanding of all physical processes that are important in the atmospheres and interiors of stars to explain their observed spectra, their internal structure and their evolution.

 

Learning Outcomes

By the end of the module the students will be able to:

 

• Solve the equation of radiation transfer for static, plane parallel model atmospheres in the gray atmosphere approximation, both analytically and numerically.
• Explain limb darkening in stellar atmospheres, and continuum and spectral line
• Understand the concept of LTE and the conditions where it applies.
• Understand the concept of the curve of growth and its significance for measuring stellar properties and element
• Be able to define and calculate Jeans' masses and densities.
• Be able to write down and explain the terms in the equations of stellar structure and solve them using simple numerical techniques.
• Understand the equation of state that provides pressure support in stellar interiors.
• Understand what is meant by a homologous model and apply it to solve the equations of stellar
• Understand and describe nuclear burning in stars including CNO cycle and pp-chain.
• Understand and describe stellar properties on the main sequence and explain post main sequence evolution and the fate of stars.

 

Synopsis

This module runs in parallel with AS4012.  All lectures and tutorials are shared with the AS4012 students, and the computational homework is assessed in the same way. The course is organised in two parts: stellar atmospheres (11 lectures) and stellar interiors (12 lectures). There are six additional tutorial sessions taking place in the lecture room with exam-like questions, which are distributed one week prior to the tutorial sessions. There are two assessed computational homework exercises to self-compute simple models for the emergent spectrum and the inner structure of solar-like stars using PYTHON, which count with 12.5% each towards to module grade.

 

 

Additional information on continuous assessment etc.

The six tutorials develop exam-style problem-solving skills. The questions will be distributed about one week prior to the tutorial sessions. Students will then be subdivided into three groups in the tutorials to discuss and compare their solutions. Complete solutions of all exam-style questions will be made available to the students afterwards on moodle.  

 

The deadlines for submitting the assessed computational homework are towards the end of week #5 and week #11.  Please note that the definitive comments on continuous assessment will be communicated within the module. 

 

Recommended Books

Please view University online record:

http://resourcelists.st-andrews.ac.uk/modules/as4012.html

 

General Information

Please also read the general information in the School's Astrophysics MSc handbook.