Synopses & Reviews
The recent research domain of asteroseismology refers to the study of the internal structure of pulsating stars through the interpretation of their frequency spectra. Asteroseismologists make great use of the oscillations to probe the stellar interior, which is not directly observable. The basic principles of asteroseismology are very much alike those developed by earth seismologists.
No part of the Universe is more difficult to observe directly than the interior of the stars. The reason why stellar interiors can be probed from oscillations is that different oscillation modes penetrate to different depths inside the star. Asteroseismology is the only available method so far to derive the internal structure of the stars with high precision.
Oscillations can be excited in stars when thermal energy is converted into kinetic energy of pulsation. Similarly as for any heat engine, this proces is effective if heat is absorbed in the high temperature phase of oscillation and emitted when the temperature is low. The main mechanism for stars is the net conversion of radiation energy into pulsational energy in the surface layers of some classes of stars. The resulting oscillations are usually studied under the assumption that they are small, and that the star is isolated and spherically symmetric.
Synopsis
Understanding the stars is the bedrock of modern astrophysics. Stars are the source of life. The chemical enrichment of our Milky Way and of the Universe withallelementsheavierthanlithiumoriginatesintheinteriorsofstars.Stars arethe tracersofthe dynamics ofthe Universe, gravitationallyimplying much more than meets the eye. Stars ionize the interstellar medium and re-ionized the early intergalactic medium. Understanding stellar structure and evolution is fundamental. While stellar structure and evolution are understood in general terms, we lack important physical ingredients, despite extensive research during recent decades.Classicalspectroscopy, photometry, astrometryandinterferometryof stars have traditionally been used as observational constraints to deduce the internal stellar physics. Unfortunately, these types of observations only allow the tuning of the basic common physics laws under stellar conditions with relatively poor precision. The situation is even more worrisome for unknown aspects of the physics and dynamics in stars. These are usually dealt with by using parameterised descriptions of, e.g., the treatments of convection, rotation, angularmomentumtransport, theequationofstate, atomicdi?usion andsettlingofelements, magneto-hydrodynamicalprocesses, andmore.There is a dearth of observational constraints on these processes, thus solar values areoftenassignedtothem.Yetitishardtoimaginethatonesetofparameters is appropriate for the vast range o
Synopsis
Asteroseismology refers to the study of the internal structure of pulsating stars through the interpretation of their frequency spectra. This is the first book available on the subject and offers a practical guide for graduate students or scientists working in the growing field of stellar astrophysics. Asteroseismology is the only available method so far to derive the internal structure of the stars with high precision. The basic principles are very much like those developed by earth seismologists. This book provides a general introduction into the research area of asteroseismology, covering all aspects from observations, methodology for data analysis, up to seismic interpretations of stars.
Synopsis
The recent research domain of asteroseismology studies the internal structure of stars, which is not directly observable, through the interpretation of the frequency spectra of stellar oscillations. The basic principles of asteroseismology are very similar to those developed by earth seismologists. Stellar interiors can be probed from oscillations because different oscillation modes penetrate to different depths inside the star. Asteroseismology is the only available method to derive the internal structure of the stars with high precision. This book - the first on asteroseismology - offers a practical guide for graduate students and scientists working in stellar astrophysics. It provides a general introduction to asteroseismology and comprehensive coverage of all its aspects: fundamental theory, observations and observational techniques, methodology of data analysis and seismic interpretations of various classes of multi-periodic pulsating stars.
Synopsis
This volume offers a practical guide to asteroseismology for graduate students and scientists involved with stellar astrophysics. It introduces asteroseismology and provides comprehensive coverage of fundamental theory, observations and techniques, in addition data analysis methods.
About the Author
Conny Aerts is full professor at the University of Leuven, Belgium, as well as professor by special appointment on the Chair Asteroseismology, University of Nijmegen, The Netherlands. Jørgen Christensen-Dalsgaard is full professor of helio- and asteroseismology at Aarhus University, Denmark. Don Kurtz is full professor at the University of Central Lancashire, UK. Their collective expertise encompasses all aspects of asteroseismology. All three authors are experienced lecturers and participate in numerous scientific committees. Their research teams enjoy international recognition and are heavily involved in various ground-based and satellite projects on asteroseismology.
Table of Contents
1 Introducing Asteroseismology.- 1.1 Introduction.- 1.2 1-D Oscillations.- 1.3 2-D Oscillations in a Drum Head.- 1.4 3-D Oscillations in Stars.- 1.5 An Asteroseismic HR Diagram for p-Mode Pulsators.- 1.6 A Pulsation HR Diagram.- 2 Stellar Oscillations across the Hertzsprung-Russell Diagram.- 2.1 Stellar Evolution in a Nutshell.- 2.2 Variability Studies from Large-Scale Surveys.- 2.3 Oscillations Near the Main Sequence.- 2.4 Oscillations in Pre-Main-Sequence Stars.- 2.5 Pulsations in Evolved Stars with M ≤ 9M.- 2.6 Pulsations in Evolved Stars with M ≥ 9M.- 2.7 Compact Oscillators.- 2.8 Pulsations in Binaries.- 2.9 Conclusions.- 3 Theory of Stellar Oscillations.- 3.1 General Hydrodynamics.- 3.2 Equilibrium Stellar Structure.- 3.3 Equations of Linear Stellar Oscillations.- 3.4 Asymptotic Theory of Stellar Oscillations.- 3.5 Computed Properties of Modes of Oscillation.- 3.6 Variational Properties of Stellar Adiabatic Oscillations.- 3.7 Driving Mechanisms.- 3.8 Effects of Rotation.- 4 Observational Techniques.- 4.1 Duty Cycle.- 4.2 Time.- 4.3 Photometry.- 4.4 Spectroscopy.- 5 Frequency Analysis.- 5.1 Harmonic Analysis by Least Squares.- 5.2 Non-parametric Frequency Analysis Methods.- 5.3 Parametric Frequency Analysis Methods.- 5.4 Significance Criteria.- 5.5 Error Estimation of the Derived Frequencies.- 5.6 The use of Weights in Merging different Data Sets.- 5.7 Damped Oscillations.- 5.8 Eliminating Aliases.- 5.9 Conclusions.- 6 ModeIdentification.- 6.1 Mode Identification from Multicolour Photometry.- 6.2 Mode Identification from High-Resolution Spectroscopy.- 6.3 Mode Identification from Combined Photometry and Spectroscopy.- 6.4 Towards Mode Identification from Combined Interferometry and Spectroscopy?.- 6.5 Towards Mode Identification from Eclipse Mapping?.- 7 Applications of Asteroseismology.- 7.1 Helioseismology.- 7.2 Solar-Like Pulsators.- 7.3 Heat Driven Main Sequence Stars.- 7.4 Compact Pulsators.- 8 The Future.- 8.1 Space Missions.- 8.2 Ground-Based Networks and Antarctica.- A Summary of the Different Classes of Stellar Pulsators.- B Properties of Legendre Functions and Spherical Harmonics.- C Mathematical Preliminaries.- D Adiabatic Oscillations in an Isothermal Atmosphere.- E Asymptotic Theory of Stellar Oscillations.- Bibliography.- Subject Index.- Object Index.- Acronym Definition Index.