Observational Astronomy

Second Edition

The long-awaited second edition of this well-received textbook gives a thorough introduction to observational astronomy. Starting with the basics of positional astronomy and systems of time, it continues with charts and catalogs covering both historically important publications and modern electronic databases. The book builds on a fundamental discussion of the basics of light and the effects of the atmosphere on astronomical observations. Chapters include discussions of optical telescopes, detectors, photometry, variable stars, astrometry, spectroscopy, and solar observations. This edition contains new discussions of measurements with CCDs and appendices give basic statistical methods, useful astronomical software and websites, and sources of accurate time calibration signals. Observational Astronomy is the perfect textbook for upper level undergraduate or beginning graduate courses on astronomy. Examples based on real astronomical data are placed throughout the text. Each of the well-illustrated chapters is supported by a set of graduated problems and suggestions for further reading.

Observational Astronomy

Second Edition

D. Scott Birney
Wellesley College,
Massachusetts

Guillermo Gonzalez
Iowa State University

David Oesper
Iowa State University

CAMBRIDGE UNIVERSITY PRESS
Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo

Cambridge University Press
The Edinburgh Building, Cambridge CB2 2RU, UK

Published in the United States of America by Cambridge University Press, New York

www.cambridge.org
Information on this title: www.cambridge.org/9780521853705

© D. S. Birney, G. Gonzalez, and D. Oesper 2006

This publication is in copyright. Subject to statutory exception
and to the provisions of relevant collective licensing agreements,
no reproduction of any part may take place without
the written permission of Cambridge University Press.

First published 2006

Printed in the United Kingdom at the University Press, Cambridge

A catalog record for this publication is available from the British Library

Library of Congress Cataloging in Publication data
Birney, D. Scott, 1926–
Observational astronomy/D. Scott Birney, Guillermo Gonzalez, David Oesper. – 2nd edn.
  p. cm.
Includes bibliographical references and index.
ISBN-13: 978-0-521-85370-5 (hardback)
1. Astronomy – Observations. 2. Astronomy – Technique. I. Gonzalez, Guillermo, 1963– II. Oesper, David, 1956– III. Title.
QB145.B52 2006
522 – dc22 2006008744

ISBN-13 978-0-521-85370-5 hardback
ISBN-10 0-521-85370-2 hardback

Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate.

Contents

Preface to the first edition

Students at the level of advanced undergraduates or beginning graduate students have often found that much information needed in the everyday practice of astronomy is not easily accessible. The necessary details are not to be expected in most textbooks, and one must often refer to early copies of some journals or to a professor’s notes. It is my intention that this book should provide students with a ready reference of a practical nature.

For many years a course in astronomical techniques has been taught at Wellesley College, and the students there have been able to apply all of the methods described here. This book is thus based on the notes which I have developed while teaching this course. Over the years I have encountered a number of excellent books which were either to serve as texts for practical courses or as general handbooks for the use of amateur astronomers. My feeling has been that none of these covered the topics which I felt were most necessary at the level which I felt could be most useful.

It is my hope that this book will fill a real need in the reference material available to astronomers at many levels.

D. Scott Birney
1991

Preface to the second edition

Many astronomy instructors adopted the first edition of Observational Astronomy as their primary text in advanced undergraduate courses. One of us (GG) used it as the primary text for an advanced undergraduate course in astronomy beginning in 1997. Unfortunately, the first edition went out of print in the late 1990s. By that time it had also become apparent that it was in need of revision. In particular, the charge coupled device (CCD) had already displaced nearly all other detectors in astronomy, but the first edition included only a short appendix on CCDs. Several chapters, instead, focused on photographic techniques. These included photometry, astrometry and spectroscopy. We have replaced all discussions of photographic techniques with CCD techniques in the present edition. We eliminated the chapters on classification of stellar spectra and radio astronomy and added chapters on light and detectors. In addition, we have reordered the material in several chapters in a way we hope is more pedagogically useful.

Most of the discussions about classical astronomical instruments, such as plate measuring engines and filar micrometers, have also been reduced or eliminated. The first edition remains a useful resource on these topics, and we encourage the interested reader to check with their local university library for copies.

The present edition of Observational Astronomy was the Master’s thesis project of David Oesper at Iowa State University.

D. Scott Birney
Guillermo Gonzalez
David Oesper
August 2005

Acknowledgements

Several people deserve credit for their help with this book. We are especially grateful to Joan A. Gonzalez. Joan provided indispensable help in creating many of the line drawings. Without her help, the text would have been much more sparsely, much less impressively illustrated. We also thank Joseph Eitter for several images and data used in preparing several plots.

The four anonymous referees provided helpful suggestions for changes to the first edition of this book. We have incorporated most of them into this new edition.