Understanding Variable Stars

✍ Scribed by John R. Percy

• Publisher: Cambridge University Press
• Year: 2007
• Tongue: English
• Leaves: 374
• Category: Library

✦ Synopsis

Variable stars are those that change brightness. They come in many varieties, but each one provides important information about the star: its properties, its internal structure, and its evolution. This book provides a concise overview of variable stars, including a historical perspective, an introduction to stars in general, the techniques for discovering and studying variable stars, and a description of the main types of variable stars. Intended for anyone with some background knowledge of astronomy, it is especially suitable for undergraduate students and experienced amateur astronomers.

✦ Table of Contents

Cover
Half-title
Title
Copyright
Contents
Boxes
Figures
Tables
Preface
1 History and development
1.1 Tycho’s and Kepler’s stars
1.2 The beginnings of modern astronomy
1.3 Systematic visual observations
1.4 The photographic revolution
1.5 Spectroscopy
1.6 Classification and explanation
1.7 Photoelectric photometry: the electronic revolution
1.8 Consolidation
1.9 The modern age
1.10 Variable stars: the present status
2 Stars
2.1 Positions
2.2 Binary and multiple stars
2.3 Star clusters
2.4 Galaxies
2.4.1 Groups and clusters of galaxies
2.5 Motions of the stars
2.6 Apparent magnitude
2.7 Distance
2.8 Absolute magnitude and luminosity
2.9 Stellar masses
2.10 Spectra
2.11 Colour
2.12 Temperature
2.13 Diameter
2.14 Composition
2.15 Rotation
2.16 Radial velocity
2.17 The Hertzsprung--Russell (H--R) diagram
2.18 Star structure
2.19 Star formation
2.20 Star evolution
2.21 Star death
3 Variable stars
3.1 Magnitude and Julian Date
3.2 Measurement of variable stars
3.2.1 Photometry
3.2.2 Spectroscopy
3.2.3 Polarimetry
3.3 Discovery and observation
3.4 Analysis of variable star data
3.4.1 Light curves
3.4.2 Times and magnitudes of maximum and minimum
3.4.3 Periods, and period determination
3.4.4 Period changes in stars
3.5 Classification
3.6 Certification
3.7 Nomenclature
3.8 Bibliography
4 Rotating variable stars
4.1 The spotted sun
4.2 Sunlike stars
4.3 FK Comae stars
4.4 RS Canum Venaticorum stars
4.5 BY Draconis stars
4.6 Peculiar A (Ap) stars
4.7 Pulsars
5 Eclipsing variable stars
5.1 Overview
5.2 Ellipsoidal variable stars
5.3 Classification of eclipsing variables
5.4 Analysis of eclipsing variables
5.4.1 Period
5.4.2 Eccentricity
5.4.3 Inclination
5.4.4 Size of the orbit and of the stars
5.4.5 Luminosity and temperature
5.4.6 Complications
Partial eclipses
Limb darkening
Gravity darkening
Reflection
Starspots
A third star
5.4.7 Analysis: Modern approaches
5.5 Detached eclipsing variables
5.6 Semi-detached binaries
5.7 WUrsae Majoris stars -- contact binaries
5.8 Symbiotic binary systems
5.9 VV Cephei stars
5.10 X-ray binaries
5.11 The evolution of binary systems
5.12 Transiting exoplanets
6 Pulsating variable stars
6.1 Pulsation modes
6.2 Pulsation mechanisms
6.3 Modelling stellar pulsation
6.4 Non-linear effects
6.5 The instability strip(s)
6.6 Helioseismology: pulsations of the sun
6.7 Asteroseismology
6.8 Classical Cepheid variable stars
6.8.1 Variability
6.8.2 Physical properties
6.8.3 Interpretation
6.9 Population II Cepheids (W Virginis stars)
6.9.1 Anomalous Cepheids
6.10 RV Tauri variables
6.11 RR Lyrae stars
6.11.1 Variability and classification
6.11.2 Period changes
6.11.3 Light curve variations: the Blazhko effect
6.11.4 Distribution and motions
6.11.5 Physical properties
6.11.6 Correlations
6.11.7 Theoretical interpretation
6.12 Delta Scuti stars
6.12.1 SX Phoenicis stars
6.12.2 Gamma Doradus stars
6.13 Rapidly oscillating peculiar A (roAp) stars
6.14 Pulsating degenerate stars
6.14.1 ZZ Ceti stars
6.14.2 Central stars of planetary nebulae
6.15 Beta Cephei (Beta Canis Majoris) stars
6.15.1 Non-radially pulsating B stars
6.15.2 Subdwarf B (sdB) stars
6.16 Pulsating red giants (PRGs)
6.16.1 Classification of pulsating red giants
6.16.2 Mira variables
Variability
Period--luminosity--colour relation
Masses
The nature of Miras
6.17 Red supergiant (SRc) variables
7 Eruptive variable stars
7.1 Flare stars
7.1.1 Variability
7.1.2 Physical properties
7.1.3 Flare mechanism
7.2 Cataclysmic variables
7.2.1 Novae
Light curves
Ultraviolet and infrared variability
Spectroscopic variability
The ejected material
7.2.2 Recurrent novae
7.2.3 Dwarf novae
Spectroscopic variability
7.2.4 Nova-like objects
7.2.5 Rapid brightness variability in cataclysmic variables
7.2.6 The Close Binary Model for Cataclysmic Variables
7.2.7 Novae and Dwarf Novae: the cause of the cataclysm
7.2.8 Symbiotic stars
7.3 Supernovae
7.3.1 Discovery
7.3.2 Brightness variability
7.3.3 Absolute magnitude at maximum
7.3.4 Frequency and distribution
7.3.5 Spectra
7.3.6 Outburst mechanism
7.3.7 Supernova remnants
7.4 Gamma-ray bursters
7.5 Active Galactic Nuclei (AGN)
8 Pre-main-sequence variable stars
8.1 T Tauri stars
8.1.1 Photometric variability
8.1.2 Spectroscopic variability
8.1.3 Physical properties
8.1.4 Binary and multiple T Tauri stars
8.1.5 Interpretation
8.2 FU Orionis stars
8.3 Herbig--Haro objects
8.4 Herbig Ae and Be stars
8.5 Putting it all together
9 Miscellaneous variable stars
9.1 Be stars -- Gamma Cassiopeiae variables
9.1.1 History
9.1.2 ‘Bumpers’
9.2 Wolf--Rayet stars
9.3 Hypergiant variable stars
9.3.1 Luminous blue variables
9.3.2 Rho Cassiopeiae and the yellow hypergiants
9.4 R Coronae Borealis (RCB) stars
10 Epilogue
10.1 Variable stars and astronomical research
10.2 Variable stars and amateur astronomy
Partnerships in Astronomy (Percy and Wilson, 2000), especially the paper by Leif
10.3 Variable stars and science education
10.4 Variable stars and the general public
Appendix: Acronyms
Bibliography
Resources
Index