Over the past decade the study of the formation and properties of interstellar grains has assumed a growing importance, going much beyond what might have been guessed only a few years ago. It has come to be understood that grains playa role in processes other than the simple absorption and scattering of starlight, which was all that the astronomers of a generation aga considered to be their relevance. Grains indeed playa critical role in controlling the temperature, composition, and states of aggregation of the whole interstellar medium. Among the still mysterious problems is the origin of the vast clouds of obscuring material that is observed in radiogalaxies like NGC 5128 and M 82, which may weIl be associated with the explosions of very massive objects. It is safe to say that from this growing field of study much still remains to be dis­ covered. The topics discussed in this volume will make clear to the reader the range and versatility of the subjects. F. HOYLE FOREWORD by THE PRINCIPAL The Symposium on Solid State Astrophysics held in July 1974 brought to University College Cardiff a large and very distinguished gathering of astronomers. It was the first time that such a collection of scholars, absorbed with the problem of the systems of outer space, had collected together in Wales, and so provided a splendid spring­ board for the researches of the newly founded group of astronomers in the Department of Applied Mathematics and Astronomy at University College.

Inhalt

I/Interstellar Dust.- On the Ratio of the Total to Selective Absorption.- Features of the Interstellar Extinction Curve.- Far-Ultraviolet Extinction in ? Scorpii.- Existence and Amount of Intergalactic Dust.- Diffuse Interstellar Band Formation in Dense Clouds.- Interstellar Extinction and Diffuse Absorption Features.- Diffuse Band Extinction and Polarization in Core-Mantle Grains.- A Review of Recent Observations of Dust in H II Regions.- Nucleation and Growth of Dust Grains (Abstract).- Formation and Flow of Dust Grains in Cool Stellar Atmospheres (Abstract).- Physical Adsorption of Hydrogen on Interstellar Graphite Grain Surfaces.- Extinction and Polarization Models.- Effects of Charged Dust Grains.- Large-Scale Ionization Fronts and the Nature and Distribution of Light Scattering Particles in the Orion Nebula.- Thermal Emission Spectra of Silicates from Planetary Nebulae.- Considerations about the Absorption Efficiency of Dust Particles in the Infrared.- On the Presence of Phyllo-silicate Minerals in Interstellar Grains.- The Influence of Grain Mantles on the Formation of Hydrogen Molecules on Grain Surfaces.- Grain Charging in H II Regions.- Optical Properties of Particulates.- Polarization Properties of Silicate-Like Grains in Circumstellar Envelopes of Late-Type Stars due to Temperature Variations.- UV Radiation Fields in Dark Clouds.- The Plausibility of Silicate-Core Ice-Mantle Grains.- How to Make Metal-Poor Stars, Redden OB Associations and Grow Mantles on Grains.- Radical Formation, Chemical Processing, and Explosion of Interstellar Grains.- Effects of Suprathermal Grains.- II/Neutron Star Physics.- Solid State Physics and Cooling of Neutron Stars.- Evidence on Neutron Star Structure from Pulsars and Related Objects.- Neutron Star Cores.- Structure of Neutron Star Cores.- List of Participants.- Index of Names.- Index of Subjects.