Review 1003
Book Review: `Observer's Guide to Stellar Evolution'
By Richard Tihany
"The Observer's Guide to Stellar Evolution" by Mike Inglis (Springer-Verlag) can be used as a quick reference to a few hundred commonly observed astronomical objects. The author also provides a comprehensive explanation of the basics of astrophysics, using the objects as illustrations of the concepts he presents within the text. Inglis meticulously discusses in great detail the methods of measurement of such essential astronomical details as distances and the use of spectral analysis of starlight to determine stars' composition and relationship to other objects. We are taken from the formation of protostars in the interstellar medium to the actual birth of a star, at the point when pressure and temperature increase enough to start the core's hydrogen-fusion reaction, producing first helium and then all other elements, known as metals to astronomers. The author imparts one of the most important concepts of astronomy in his handling of the Hertzsprung-Russell Diagram, a compilation of research named in 1911 for Danish astronomer Ejnar Hertzsprung and, in 1913, for American astronomer Henry Norris Russell. He repeatedly approaches the H-R diagram from several avenues, including measurements of the radii of stars and consideration of every possible facet of a star's genesis, life and death. Inglis deals with the H-R diagram more effectively than many authors by the deftness with which he reapproaches the subject time after time. Rather than creating the impression of being overbearing and too repetitive, Inglis increases the reader's understanding of the H-R diagram's importance to the concepts under consideration. His explanation of the crux of the H-R diagram, the diagonal band of stars know collectively as the "main sequence," is key to any further understanding of astronomy, for these stars comprise 90% of all visible stars. Inglis' explanation of the "proton-proton chain," the series of nuclear reactions by which four hydrogen atoms interact at extremely high temperatures to form one helium atom, is the best I've read. His lucid description of helium burning, which results in the creation of carbon and oxygen, couldn't be clearer. The next main event in the sequence, the "helium flash," only happens in low-mass stars but is best described as spectacular: energy output about 100 times greater than the entire Milky Way. The temperature of the star's core at this point can reach 300 million K. Due deference to the mathematically-challenged is provided by Inglis' decision to keep nearly all formulas and computations separate from the text in shaded boxes scattered throughout the book. The book's diagrams are well-done and informative. I intend to plan some observing sessions in the near future by referring to the object descriptions. Notably missing is an effective and comprehensive glossary. This necessitates frequent use of the index, a poor substitute. While this book is the product of a talented astronomer, it reveals the worst example of copyediting I've seen in years. The reader is forced to reread many sentences and to guess their meaning. In fact, only a determined reader is likely to finish the book. The author knows better than to say (page 36), "It is easier to have an idea of a star if we say it is about 10 times as hotter (sic) than the Sun..." Or, (page 73) "...they can in affect (sic) sweep away the residual gas and dust clouds...." On page 101, Inglis tells us that a star cluster "...can vary from a few dozen light years to about 70 light years across...." (70 is a few dozen.) On page 117, he states, "The mechanisms by which provides the `triggers' for star formation have three very disparate origins..."(By which what provides the triggers?) I was repeatedly left with the impression that Springer is selling a fairly thin paperback for $44.95 which could be more aptly identified as a rough draft than a book. However, the factual content is valuable despite the nearly fatal defects. This impression is largely due to my knowledge of astronomy before venturing into this prematurely-published minefield. Had I paid for the book rather than been provided a review copy, I would have been tempted to return it. The current edition of this book could be the makings of a rather good book if Inglis, his editor and his publisher decide to complete the project.