Fundamentals of Solar Astronomy Arvind Bhatnagar and William Livingston , World Scientific, Hackensack, NJ, 2005. $58.00, $32.00 paper (455 pp.). ISBN 981-238-244-5, ISBN 981-256-357-1 paper
Like most areas of astronomical research, the study of our Sun is now a multi-wavelength enterprise involving a diverse group of researchers with expertise in various instrumental, analytical, and theoretical techniques. With the public’s excitement over dramatic satellite images from space, it is easy to forget that only a few decades ago the field was almost entirely dependent on ground-based observations in the visible part of the electromagnetic spectrum. Arvind Bhatnagar and William Livingston’s Fundamentals of Solar Astronomy is a welcome reminder by two distinguished solar-optical astronomers of the important role that those ground-based observations have played and continue to play in solar research.
According to the preface and back cover, the book’s purpose is to stimulate interest in studying and observing the Sun and to bridge the gap between books that provide elementary information about the Sun and advanced texts on solar astrophysics. The authors state that their book is primarily aimed at university students and amateur astronomers who are “starting to study the Sun and want to pursue an advanced course in solar physics, but lack the basic knowledge of solar astronomy.” However, they do not pursue the careful pedagogical development that is the hallmark of a good textbook. In fact, it is best not to read it from beginning to end: The level of exposition ranges from informal to difficult. Although it contains few equations, the reader will need to have mastered basic physics and have a good knowledge of astronomy, optics, and calculus to follow much of the text. A glossary helps with the terminology. The English in the book is not uniformly correct, but the authors’ intent is generally clear.
The book’s packaging is quite attractive. Its front cover displays an intriguing image of a Sun god from India; the back shows pictures of Bhatnagar, who passed away in May, and Livingston. The text contains many photographs, illustrations, and graphs, some in full color. The first chapter, “Ancient Solar Astronomy,” provides an interesting compilation of ancient mythologies and observatories from around the world—from the Middle East and Asia to the Americas and Europe. However, the text reads like a concise encyclopedia. Additional references would have been helpful for readers seeking more information.
Chapter 2, “Modern Solar Observatories,” is also encyclopedic in nature. The sections on ground-based, optical facilities and current space missions are reasonably comprehensive. But in the section on solar-radio observatories, many major facilities, such as the Nançay Radioheliograph in France and the New Jersey Institute of Technology’s Owens Valley Solar Array in California, are surprisingly absent. Chapter 3, “Structure of Solar Atmosphere,” is primarily about the solar interior, and I would have combined it with chapter 9, “Solar Interior and Helioseismology.” Chapters 4 and 5 cover “The Quiet Sun” and “The Active Sun,” respectively.
Readers need to be on alert for occasional errors. In chapter 3, for example, g, the gravitational acceleration, appears in the ideal gas law. Also, the authors incorrectly state that “conduction occurs only in solids and is irrelevant for stars and Sun.” After the authors correctly show that the gyro-frequency is independent of density, chapter 4 contains the statement “The gyro-frequency of radio emission is a function of density and magnetic field strength.”
Chapters 6 through 8 address “Observational Techniques,” “Solar Optical Instrumentation,” and “Solar Eclipses,” respectively. Those chapters include such practical issues as evaluating and determining the orientation of the Sun, the position of the Sun’s features, the types of solar-optical telescopes, and eclipse seasons and paths. The authors also offer a section on determining the gross properties of the Sun (distance, mass, luminosity, and so forth), as well as technical sections on optical filters and different measures of temperature. Although the authors cover a range of topics, their emphasis and greatest strength are in the area of ground-based, solar-optical astronomy. The final chapter, “On the Joy of Observing the Sun—A Personal Experience,” is a delightful, approximately two-page essay that I would have placed at the front of the book.
Bhatnagar and Livingston frequently make the case for the continued value of observing the Sun with the human eye. The book presents fascinating comparisons of the detail in historic drawings of the Sun with modern high-resolution photographs. Chapter 8 encourages first-time solar-eclipse observers to leave their cameras at home and experience the sensations of an eclipse. Moreover, it includes a list of phenomena that can be observed with no more than a dark filter.
Fundamentals of Solar Astronomy could have been more effective for students and amateur astronomers. Nevertheless, it contains useful, interesting information for all readers. The authors’ personal comments are priceless, and I am glad to have their book available on my shelf.
