Astrophysics of the Sun

Astrophysics of the Sun

Book Reviews Astrophysics of the Sun by Harold Zirin. Cambridge University Press, 1988,433~. (ISBN o-521-316073). PROF!S~R ZIRINclaims in his preface ...

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Book Reviews Astrophysics of the Sun by Harold Zirin. Cambridge University Press, 1988,433~. (ISBN o-521-316073). PROF!S~R ZIRINclaims in his preface that this book is not merely a revision of his venerable text The Solar Atmosphere, but rather represents a completely new version. It is true that he has rewritten most of the earlier book, but the thrust remains the same as that of TheSolar Atmosphere.Onlypart of one chapter (Chapter 6) is devoted to the solar interior and observations relating to it, and, unfortunately, the description of the methods used to construct a solar model are remarkably out of date. Little is said about the soiar neutino problem, and the implications of the solar “5minute” oscillations on the structure of the interior are somewhat misleading. In general, the understanding of the solar interior is portrayed as being in better shape than is probably justified. However, this section of the book is quite small and clearly not of primary interest to the author. The remainder, and by far the greatest part of the book, deals in glorious detail with the phenomena of the outer layers of the Sun generally known as the solar atmosphere. Here the author is more at home. However, there are still details that are a bit bothersome and are left over from his earlier book. For example, he defines (p. 59) local thermodynamic equilibrium (LTE) to occur when the source function of the radiation field is the Planck hmction. While this is a sufficient condition, it is not a necessary one. Indeed, in hot stars where electron scattering is an important source of opacity, the conditions of the gas associated with LTE will occur when the source function is far from the Planck function. The restrictive definition of a general concept such as LTE to the specific conditions in the

Evolotioa of the Lewishm and Comparable Precambrian High Grade Terrains edited by R. G. Park and J. Tarney. Geological Society Special Publication 27, Blackwell Scientific Publications, 1987,3 ISp., $80.00 (ISBN O-632-01683-3). THE BOOK isA COMPIJATIONof twenty-four papers presented at the Third Lewisian conference held at Leicester University, England, in March of 1985. Although only three of the twenty-four papers contain the word “geochemistry” in their titles, this volume, as a whole, contains a wealth of geochemical data on the Lewisian. Tarney and Weaver discuss the geochemistry of the Archean Scourian gramtlites as well that of the Proterozoic Scourian dykes. Rollinson and Fowler describe the geochemistry and petrogenesis of the Scourian at Gruimud Bay, and Rock presents some long overdue data on the chemistry of Lewisian marbles. Fettes and Mendum include some useful geochemical data in their comprehensive account of the geologic evolution of the Lewisian in its Outer Hebridean type area. Other papers on the Lewisian include three on metamorphism and thermal models, five on structure, and three on geophysics. These latter include one on deep crustal structure, one on deep seismic reflection profiling, and one on ~ieoma~etism. Comparable Precambrian high grade terrains are discussed in tbe last six papers of the volume. The first three of these are concerned with the more westerly portions of the North Atlantic cmton, including

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Sun is unfortunate and unnecessary. Another item that I found bothersome is that the index is rather skimpy and many common entries have been left out. However, in the area of presenting observational phenomena, Professor Zirin does a lovely job with a ~~ld~n~y complex volume of material. The large chapters on the chromosphere and corona are clearly written, well organized and beautifully illustrated within the production constraints of the book. Where the nature of the subject is such as to emphasize a generally phenomenological approach, Zirin is at his best. The descriptions of various aspects of the active Sun are clearly and completely described. The writing style is uncommonly easy to read and the occasional humor adds a most refreshing and unexpected touch to what could otherwise be made dreary and tedious. This is not a book for someone who wishes to understand the astrophysics of the solar interior or the relationship of the Sun to other stars. But for one who wishes to become acquainted with the myriad of phenomena associated with the outer layers of the Sun, this book is a must. I have to confess that I sympathize with Professor Zirin’s lament over the decline in the study of the Sun by contemporary astronomers. Since I believe that any educated astronomer should be acquainted with solar phenomena and since this book describes much of that phenomena better than any other, all astronomers should acquire and read it. Department ofAstronomy The Ohio State University Columbus, OH 43210, U.S.A.

George W. Collins, II

East Greenland, central West Greenland and northern Labrador (Nain province), and a paper by Hall et al. on the geochemistry of midArchean basic met&igneous rocks in southern West Greenland. The last three papers cover the Yilgarn Block of Western Australia, Enderby Land in Antartica, and eastern Hebei Province in Northeast China. The volume is dedicated to the memory of Professor Janet Watson, whose last illness prevented her from attending the conference. Her introductory paper (coauthored with Sutton) describes the present Lewisian studies as comprising a third stage (on geologic processes), following earlier stages of first mapping and then dating these rocks. A second introduction by Park and Tamey provides a usehrl summary of the conference and of the present state of knowledge concerning the Lewisian, which, as they point out, bears many similarities to Pr~mb~an high grade terrains the world over. Indeed, the theme of conference and volume appears to be that the Lewisian complex can be best understood in the broad general context of Precambrian terrains, their petrogenesis, geochemistry and tectonic models being remarkably similar in different cratonic regions. Departmentof Geology and GeoiogicaiEngineering Universityof Idaho Moscow,ID 83843, U.S.A.

Valerie E. Chamberlain