The main purpose of this book is to serve as a university textbook for a first course in astronomy. However, we believe that the audience will also include many serious ama­ teurs, who often find the popular texts too trivial. The lack of a good handbook for am­ ateurs has become a problem lately, as more and more people are buying personal com­ puters and need exact, but comprehensible, mathematical formalism for their programs. The reader of this book is assumed to have only a standard high-school knowledge of mathematics and physics (as they are taught in Finland); everything more advanced is usually derived step by step from simple basic principles. The mathematical background needed includes plane trigonometry, basic differential and integral calculus, and (only in the chapter dealing with celestial mechanics) some vector calculus. Some mathematical concepts the reader may not be familiar with are briefly explained in the appendices or can be understood by studying the numerous exercises and examples. However, most of the book can be read with very little knowledge of mathematics, and even if the reader skips the mathematically more involved sections, (s)he should get a good overview of the field of astronomy. This book has evolved in the course of many years and through the work of several authors and editors. The first version consisted of lecture notes by one of the editors (Oja).

Inhalt

1. Introduction.- 1.1 The Role of Astronomy.- 1.2 Astronomical Objects of Research.- 1.3 The Scale of the Universe.- 2. Spherical Astronomy.- 2.1 Spherical Trigonometry.- 2.2 The Earth.- 2.3 The Celestial Sphere.- 2.4 The Horizontal System.- 2.5 The Equatorial System.- 2.6 The Ecliptic System.- 2.7 The Galactic Coordinates.- 2.8 Perturbations of Coordinates.- 2.9 Constellations.- 2.10 Star Catalogues and Maps.- 2.11 Positional Astronomy.- 2.12 Time Reckoning.- 2.13 Astronomical Time Systems.- 2.14 Calendars.- 2.15 Exercises.- 3. Observations and Instruments.- 3.1 Observing Through the Atmosphere.- 3.2 Optical Telescopes.- 3.3 Detectors.- 3.4 Radio Telescopes.- 3.5 Other Wavelength Regions.- 3.6 Instruments of the Future.- 3.7 Other Forms of Energy.- 3.8 Exercises.- 4. Photometric Concepts and Magnitudes.- 4.1 Intensity, Flux Density and Luminosity.- 4.2 Apparent Magnitudes.- 4.3 Magnitude Systems.- 4.4 Absolute Magnitudes.- 4.5 Extinction and Optical Thickness.- 4.6 Exercises.- 5. Radiation Mechanisms.- 5.1 Radiation of Atoms and Molecules.- 5.2 The Hydrogen Atom.- 5.3 Quantum Numbers, Selection Rules, Population Numbers.- 5.4 Molecular Spectra.- 5.5 Continuous Spectra.- 5.6 Blackbody Radiation.- 5.7 Other Radiation Mechanisms.- 5.8 Radiative Transfer.- 5.9 Exercises.- 6. Temperatures.- 6.1 Exercises.- 7. Celestial Mechanics.- 7.1 Equations of Motion.- 7.2 Solution of the Equation of Motion.- 7.3 Equation of the Orbit and Kepler's First Law.- 7.4 Orbital Elements.- 7.5 Kepler's Second and Third Law.- 7.6 Orbit Determination.- 7.7 Position in the Orbit.- 7.8 Escape Velocity.- 7.9 Virial Theorem.- 7.10 The Jeans Limit.- 7.11 Exercises.- 8. The Solar System.- 8.1 An Overview.- 8.2 Planetary Configurations.- 8.3 Orbit of the Earth.- 8.4 Orbit of the Moon.- 8.5 Eclipses and Occultations.- 8.6 Albedos.- 8.7 Planetary Photometry, Polarimetry and Spectroscopy.- 8.8 Thermal Radiation of the Planets.- 8.9 The Structure of Planets.- 8.10 Planetary Surfaces.- 8.11 Atmospheres and Magnetospheres.- 8.12 Mercury.- 8.13 Venus.- 8.14 The Earth and the Moon.- 8.15 Mars.- 8.16 Asteroids.- 8.17 Jupiter.- 8.18 Saturn.- 8.19 Uranus, Neptune and Pluto.- 8.20 Minor Bodies of the Solar System.- 8.21 Cosmogony.- 8.22 Other Solar Systems.- 8.23 Exercises.- 9. Stellar Spectra.- 9.1 Measuring Spectra.- 9.2 The Harvard Spectral Classification.- 9.3 The Yerkes Spectral Classification.- 9.4 Peculiar Spectra.- 9.5 The Hertzsprung-Russell Diagram.- 9.6 Model Atmospheres.- 9.7 What Do the Observations Tell Us.- 10. Binary Stars and Stellar Masses.- 10.1 Visual Binaries.- 10.2 Astrometric Binary Stars.- 10.3 Spectroscopic Binaries.- 10.4 Photometric Binary Stars.- 10.5 Exercises.- 11. Stellar Structure.- 11.1 Internal Equilibrium Conditions.- 11.2 Physical State of the Gas.- 11.3 Stellar Energy Sources.- 11.4 Stellar Models.- 11.5 Exercises.- 12. Stellar Evolution.- 12.1 Evolutionary Time Scales.- 12.2 The Contraction of Stars Towards the Main Sequence.- 12.3 The Main Sequence Phase.- 12.4 The Giant Phase.- 12.5 The Final Stages of Evolution.- 12.6 The Evolution of Close Binary Stars.- 12.7 Comparison with Observations.- 12.8 The Origin of the Elements.- 13. The Sun.- 13.1 Internal Structure.- 13.2 The Atmosphere.- 13.3 Solar Activity.- 14. Variable Stars.- 14.1 Classification.- 14.2 Pulsating Variables.- 14.3 Eruptive Variables.- 14.4 Exercises.- 15. Compact Stars.- 15.1 White Dwarfs.- 15.2 Neutron Stars.- 15.3 Black Holes.- 16. The Interstellar Medium.- 16.1 Interstellar Dust.- 16.2 Interstellar Gas.- 16.3 Interstellar Molecules.- 16.4 The Formation of Protostars.- 16.5 Planetary Nebulae.- 16.6 Supernova Remnants.- 16.7 The Hot Corona of the Milky Way.- 16.8 Cosmic Rays and the Interstellar Magnetic Field.- 17. Star Clusters and Associations.- 17.1 Associations.- 17.2 Open Star Clusters.- 17.3 Globular Star Clusters.- 18. The Milky Way.- 18.1 Methods of Distance Measurement.- 18.2 Stellar Statistics.- 18.3 The Rotation of the Milky Way.- 18.4 The Structure and Evolution of the Milky Way.- 18.5 Exercises.- 19. Galaxies.- 19.1 The Classification of Galaxies.- 19.2 Elliptical Galaxies.- 19.3 Spiral Galaxies.- 19.4 Lenticular Galaxies.- 19.5 Luminosities of Galaxies.- 19.6 Masses of Galaxies.- 19.7 Systems of Galaxies.- 19.8 Distances of Galaxies.- 19.9 Active Galaxies and Quasars.- 19.10 The Origin and Evolution of Galaxies.- 20. Cosmology.- 20.1 Cosmological Observations.- 20.2 The Cosmological Principle.- 20.3 Homogeneous and Isotropic Universes.- 20.4 The Friedmann Models.- 20.5 Cosmological Tests.- 20.6 History of the Universe.- 20.7 The Future of the Universe.- Appendices.- A. Mathematics.- A.1 Geometry.- A.2 Taylor Series.- A.3 Vector Calculus.- A.4 Conic Sections.- A.5 Multiple Integrals.- A.6 Numerical Solution of an Equation.- B. Quantum Mechanics.- B.1 Quantum Mechanical Model of Atoms. Quantum Numbers.- B.2 Selection Rules and Transition Probabilities.- B.3 Heisenberg' Uncertainty Principle.- B.4 Exclusion Principle.- C. Theory of Relativity.- C.1 Basic Concepts.- C.2 Lorentz Transformation. Minkowski Space.- C.3 General Relativity.- C.4 Tests of General Relativity.- D. Radio Astronomy Fundamentals.- D.1 Antenna Definitions.- D.2 Antenna Temperature and Flux Density.- E. Tables.- Further Reading.- Photograph Credits.