AS4012 The Physics of Nebulae and Stars 2
Academic year
2024 to 2025 Semester 2
Curricular information may be subject to change
Further information on which modules are specific to your programme.
Key module information
SCOTCAT credits
15
SCQF level
SCQF level 10
Availability restrictions
Not automatically available to General Degree students
Module Staff
TBC
Module description
This module develops the physics of stellar interiors and atmospheres from the basic equations of stellar structure introduced in AS2001/AS2101 using the 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-requisites
BEFORE TAKING THIS MODULE YOU MUST PASS AS4011
Assessment pattern
2-hour Written Examination = 75%, Coursework = 25%
Re-assessment
Oral Re-assessment, capped at grade 7
Learning and teaching methods and delivery
Weekly contact
3 lectures occasionally replaced by whole-group tutorials.
Scheduled learning hours
33
Guided independent study hours
117
Additional information from school
Aims & Objectives
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
The course is organised in two parts: stellar atmospheres (11 lectures) and stellar interiors (10 lectures). There are ten weekly workshop sessions taking place in the lecture room with exam-like questions, which are distributed one week prior to the workshop sessions. AS4012 students choose ONE of two assessed computational homework exercises to self-compute simple models for the emergent spectrum and the inner structure of solar-like stars using Python, each of which count 25% towards the module grade.
Additional information on workshops and continuous assessment
Please note that the definitive arrangements for continuous assessment will be communicated within the module. This section is intended to give an indication of the likely breakdown and timing of the continuous assessment.
The ten workshops develop exam-style problem-solving skills. The questions will be distributed about one week prior to the sessions. Students will be subdivided into small groups in the workshops 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 likely to be towards the end of weeks 5 and 11, depending on which project is chosen.
Accreditation Matters
This module may not contain material that is part of the IOP “Core of Physics”, but does contribute to the wider and deeper learning expected in an accredited degree programme. The skills developed in this module, and others, contribute towards the requirements of the IOP “Graduate Skill Base”.
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 Honours handbook that is available via https://www.st-andrews.ac.uk/physics-astronomy/students/ug/timetables-handbooks/.