User:Tohline/H Book

Preface from the original version of this HyperText Book (H_Book):

November 18, 1994

Much of our present, basic understanding of the structure, stability, and dynamical evolution of individual stars, short-period binary star systems, and the gaseous disks that are associated with numerous types of stellar systems (including galaxies) is derived from an examination of the behavior of a specific set of coupled, partial differential equations. These equations -- most of which also are heavily utilized in studies of continuum flows in terrestrial environments -- are thought to govern the underlying physics of all macroscopic "fluid" systems in astronomy. Although relatively simple in form, they prove to be very rich in nature.

The literature on this subject is enormous, as serious discussions of the structure and dynamical properties of stars and galaxies date back more than a century. Although a reasonable attempt is made here to review this vast literature and to provide a bridge between discussions that traditionally have focused on stellar structure and those that have focused on galaxy disks, the primary purpose of this work is two-fold:

• To document in an electronically accessible format many of the key physical principles that underlie modern discussions of the structure, stability, and dynamical evolution of astrophysical fluid systems;

• To take advantage of the added dimensions offered by the hypertext medium -- such as color, text/equation linkages, animation, VRML, and access to online computational algorithms-- to effectively illustrate many of these physical principles.

Context

Principal Governing Equations

Supplemental Relations

Virial Equations

Applications

Structure

Stability

Dynamics