Advances in Astronomy and Astrophysics, Volume 6 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with the description of improved methods for analyzing and classifying families of periodic orbits in a conservative dynamical system with two degrees of freedom. The next chapter describes the variation of fractional luminosity of distorted components of close binary systems in the course of their revolution, or the accompanying changes in radial velocity. This topic is followed by discussions on various mechanisms that have been proposed for the interstellar medium, as well as the mass exchange and evolution of close binary stars. The concluding chapter examines evidence for lunar luminescence. This book will prove useful to astronomers and astrophysicists.

Advances in Astronomy and Astrophysics, Volume 3 is a collection of papers that describes the elements found in the solar atmosphere, Fourier transforms, internal structure of the stars, and apsidal motions. Two papers discuss the spectral analysis of solar flares and a survey of modern cosmology. One paper discusses the solar abundance of particular elements such as iron, sodium, potassium, zinc, gallium, strontium. The loss of heavier elements from the upper layers of the solar atmosphere depends on the atomic number: the heavier the atom the greater the amount of depletion. Another paper describes a method to determine the elements of an eclipsing binary system by defining the characteristic functions of the eclipse derived from some integral transforms of the ascending and descending parts in minima of the light curve. One paper compares the general physical theory of self-gravitating gas spheres and of thermonuclear processes with certain phenomena present in close binary systems. One paper notes that the estimates of electron density made by various methods at different flares (solar) and the resulting optical thickness of flares yield values within a wide range. The differences observed in optical thickness are due to various presuppositions on the broadening mechanism of the Balmer lines. The collection is suitable for astronomers, geochemists, astro-physicists, and scientists whose works involve cosmology.

Advances in Astronomy and Astrophysics, Volume 5 is a collection of papers that deals with the Zodiacal light, three dimensional periodic oscillations, the secular variation of mass, and the evolution of binary systems. Some papers discuss the periodicity of the sunspot groups, as well as compact and dispersed cosmic matter. One paper notes that the brightness of the zodiacal light continues to increase right up to the limb of the Sun, where it merges with parts of the solar corona. Another paper discusses analytically and numerically the three families of three-dimensional motions where the members of each family pass very close to one of three equilibrium points. One paper describes the loss of mass in the Sun as being (1) caused by electromagnetic or corpuscular radiation that occurs at a slow rate, or (2) by an explosion of a nova or supernova. One paper examines the periodicity of solar activities, the physical conditions of sunspots, chromospheric flares, prominence, and magnetic fields. The paper notes that different periodicity laws govern the formation frequency and importance of spot groups. The behavior of spot groups also depends on the periodicity process of solar activity. The collection can prove valuable for astro-physicists, astronomers, geochemists, and mathematicians whose works involve cosmology and astronomy.

Advances in Astronomy and Astrophysics, Volume 2 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of six chapters and begins with a summary of observational record on twilight extensions of the Venus cusps. The next chapter deals with the common and related properties of binary stars, with emphasis on the evaluation of their cataclysmic variables. Cataclysmic variables refer to an object in one of three classes: dwarf nova, nova, or supernova. These topics are followed by discussions on the eclipse phenomena and the eclipses in the domain of the radio waves and of the artificial satellites. A chapter discusses the discovery, colors, spectra, motions, luminosities, and frequency in space of white dwarf stars. The concluding chapters examine the occurrence and capture of stray bodies in the solar system and the existence of Magellanic clouds. This book will prove useful to astronomers and astrophysicists.

Advances in Astronomy and Astrophysics, Volume 4 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with a description of objective prism and its application in space observations. The next chapter deals with the possibilities of deriving reliable models of the figure, density distribution, and gravity field of the Moon based on data obtained through Earth-bound telescopes. These topics are followed by a discussion on the ideal partially relativistic, partially degenerate gas in an exact manner. A chapter examines first the effect of exchange of matter on the periods of close binary systems, and then briefly surveys the mechanisms of mass loss, other causes of period changes, and related evolutionary problems. The last chapter looks into the cometary origin of meteorites. This book will prove useful to astronomers and astrophysicists.

Advances in Astronomy and Astrophysics, Volume 9 covers reviews on the advances in astronomy and astrophysics. The book presents reviews on the Roche model and its applications to close binary systems. The text then describes the part played by lunar eclipses in the evolution of astronomy; the classical theory of lunar eclipses; deviations from geometrical theory; and the methods of photometric observations of eclipses. The problems of other phenomena related in one way or another to lunar eclipses are also considered. The book further tackles the infrared observation on the eclipsed moon, as well as some of the experimental measurements at infrared wavelengths which have proved useful in evaluating various theoretical models and, more generally, in specifying the radiation environment on the lunar surface. Astronomers, astrophysicists, and students taking related courses will find the book invaluable.

Advances in Astronomy and Astrophysics, Volume 1 brings together numerous research works on different aspects of astronomy and astrophysics. This book is divided into five chapters and begins with an observational summary of the shock-wave theory of novae. The subsequent chapter provides the properties and problems of T tauri stars and related objects. These topics are followed by discussions on the structure and origin of meteorites and cosmic dust, as well as the models for evaluation of mass distribution in oblate stellar systems. The final chapter describes the methods of polarization measurements of starlight. This book is of value to astronomers, astrophysicists, and researchers in the allied fields.

Advances in Astronomy and Astrophysics, Volume 7 covers reviews about the advances in astronomy and astrophysics. The book presents reviews on the scattering of electrons by diatomic molecules and on Babcock’s theory of the 22-year solar cycle and the latitude drift of the sunspot zone. The text then describes reviews on the structures of the terrestrial planets (Earth, Venus, Mars, Mercury) and on type III solar radio bursts. The compact and dispersed cosmic matter is also considered with regard to the search for new cosmic objects and phenomena and on the nature of the ref shift from compact galaxies. Astronomers and astrophysicists will find the book invaluable.

Advances in Astronomy and Astrophysics, Volume 8 presents reviews on the advances in astronomy and astrophysics. The book discusses microwave studies of thermal emission from the moon; the origin of the thermal emission of the moon at microwave frequencies; and the effect of various specific surface attributes on the characteristics of the microwave emission. The text then describes radar studies of the moon, including radar studies of the moon’s motions and of the statistical properties of the lunar surface and radar mapping of the lunar surface. The theoretical basis of cratering and erosion of the moon’s surface is also considered. Astronomers, astrophysicists, and students taking astronomy and astrophysics will find the book useful.