Variable Stars

1. General Introduction.- 1.1 Introduction and General Summary.- 1.2 Explanation of Some Fundamental Concepts.- 1.3 Light-Curves and Periods.- 1.4 Julian Date and the Expression of Dates and Times.- 1.5 Nomenclature of Variable Stars.- 2. Pulsating Variables.- 2.1 Classical Pulsating Stars.- 2.1.1 Historical Summary and Classification.- 2.1.2 ? Cephei and W Virginis Stars.- 2.1.3 RR Lyrae Stars.- 2.1.4 ? Scuti Stars.- 2.2 Slowly-Varying, Pulsating Stars.- 2.2.1 Mira Stars.- 2.2.2 Semiregular, Irregular and RV Tauri Stars.- 2.3 Non-Radial Pulsators.- 2.3.1 ? Cephei Stars.- 2.3.2 ZZ Ceti Stars.- 3. Eruptive Variables.- 3.1 Eruptive Binaries.- 3.1.1 Cataclysmic Variables - a Summary.- 3.1.2 Novae.- 3.1.3 U Geminorum Stars.- 3.1.4 AM Herculis Stars or Polars.- 3.1.5 Properties and Models of Cataclysmic Variables.- 3.1.6 Symbiotic Stars.- 3.1.7 X-Ray Binaries.- 3.2 Supernovae.- 3.3 Stars at an Extremely Early Stage of Evolution.- 3.3.1 Historical.- 3.3.2 T Tauri Stars and Related Objects.- 3.3.3 Flare Stars.- 3.4 Hot Variables with Extended Shells.- 3.4.1 S Doradus-Type Variable Supergiants.- 3.4.2 ? Cassiopeiae Stars.- 3.4.3 Variability in Planetary Nebulae or Their Central Stars.- 3.5 R Coronae Borealis Stars.- 3.6 ?-Ray Bursters.- 3.7 Other Types of Object.- 3.7.1 BY Draconis Stars and Similar Objects.- 3.7.2 Pulsars.- 3.7.3 ?2 Canum Venaticorum (Magnetic) Stars.- 4. Eclipsing Stars.- 4.1 General.- 4.2 Geometrical Properties.- 4.3 Classification.- 4.4 Analysis of the Light-Curve.- 4.5 Period Changes.- 4.5.1 Periodic Changes.- 4.5.2 Non-Periodic Changes.- 4.6 Statistics.- 4.7 Some Interesting Eclipsing Systems.- 4.8 Concluding Remarks on the Evolution of Close Binary Systems.- 5. Supplement to the Classification.- 5.1 Variables in Clusters.- 5.1.1 Open Clusters.- 5.1.2 Globular Clusters.- 5.2 Variables in Extragalactic Systems.- 5.2.1 Magellanic Clouds.- 5.2.2 Other Extragalactic Systems.- 5.3 Active Galaxies.- 5.3.1 General.- 5.3.2 Seyfert Galaxies.- 5.3.3 Quasars.- 5.3.4 BL Lacertae Objects.- 6. The Discovery of Variable Stars.- 6.1 Basic Considerations.- 6.2 Methods and Instruments.- 6.3 The Theory of Discovery Probability.- 6.4 Determination of Discovery Probability from Given Light-Curves.- 6.5 Comparison of Theoretical and Empirical Discovery Probabilities - The Influence of Observer and Method.- 6.6 Discovery Statistics.- 6.7 Preliminary Designations of Variable Stars.- 7. The Significance of Variable Stars for Research on the Structure of the Galaxy and Stellar Evolution.- 7.1 Methods.- 7.2 Results.- 7.3 The Galactic Halo.- 7.4 Remarks on the Evolution of the Galaxy.- 8. Observational Methods and Organizations.- 8.1 Observations.- 8.1.1 Photometric Observations.- 8.1.2 Spectrographic and Other Observations.- 8.1.3 Bright Variables.- 8.1.4 Amateur Collaboration.- 8.2 Organization.- 9. Literature.- 9.1 Brief Notes About Stellar Catalogues and Atlases.- 9.2 General Summaries, Compilations and Review Articles.- 9.3 References.- Star Index.