Estrellas variables

Understanding Variable Stars
Variable stars are those that change brightness. Their variability may be due to
geometric processes such as rotation, or eclipse by a companion star, or physical
processes such as vibration, flares, or cataclysmic explosions. In each case, variable stars
provide unique information about the properties of stars, and the processes that go on
within them.
Thisbook 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. It ends
with short reflections about the connection between the study of variable stars, and
research, education, amateur astronomy, and public interest inastronomy. This book is
intended for anyone with some background knowledge of astronomy, but is especially
suitable for undergraduate students and experienced amateur astronomers who can
contribute to our understanding of these important stars.
John R. P ercy is a Professor of Astronomy and Astrophysics at the University of
Toronto, based at the University of Toronto in Mississauga (UTM). Hisresearch interests
include variable stars and stellar evolution, and he has published over 200 research
papers in these fields. He is also active in science education (especially astronomy) at all
levels, throughout the world. His education interests and experiences include: teaching
development at the university level, development of astronomy curriculum for Ontario
schools, development ofresources for educators, pre-service and in-service teacher
education, lifelong learning, public science literacy, the roles of science centres and
planetariums, the role of skilled amateurs in research and education, high school and
undergraduate student research projects, international astronomy education and
development, and multicultural astronomy. He is Director of the undergraduate ScienceEducation program, and the Early Teacher Program at UTM, and is cross-appointed to
the Ontario Institute for Studies in Education.
He has served as President of the Royal Astronomical Society of Canada, the Royal
Canadian Institute, the American Association of Variable Star Observers, the
International Astronomical Union Commissions on Variable Stars, and on Astronomical
Education, and ofthe Astronomical Society of the Pacific. He was recently the recipient
of the Royal Canadian Institute’s Sandford Fleming Medal for contributions to public
awareness and appreciation of science and technology, the U of T School of Continuing
Studies’ Citation for Exceptional Commitment and Achievement in adult learning, and
the Distinguished Educator Award of the Ontario Institute for Studies inEducation. In
1999, he was elected a fellow of the American Association for the Advancement of
Science. In 2003, he received the University of Toronto’s Northrop Frye Award for
exemplary linkage of teaching and research. His most recent book, co-edited with Jay M.
Pasachoff, is Teaching and Learning Astronomy (Cambridge University Press, 2005).

Understanding
Variable Stars
John R. PercyUniversity of Toronto, Toronto, Ontario, Canada
CAMBRIDGE UNIVERSITY PRESS
Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo
Cambridge University Press
The Edinburgh Building, Cambridge CB2 8RU, UK
First published in print format
ISBN-13 978-0-521-23253-1
ISBN-13 978-0-511-28514-1
© J. Percy 2007
2007
Information on this title: www.cambridge.org/9780521232531
Thispublication is in copyright. Subject to statutory exception and to the provision of
relevant collective licensing agreements, no reproduction of any part may take place
without the written permission of Cambridge University Press.
ISBN-10 0-511-28662-7
ISBN-10 0-521-23253-8
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