Theoretical And Observational Consequences Of Stellar Rotation And Magnetic Fields In Stellar Winds

Rotation is ubiquitous at each step of stellar evolution, from star formation to the final stages, and it affects the course of evolution, the timescales and nucleosynthesis. Stellar rotation is also an essential prerequisite for the occurrence of Gamma-Ray Bursts. In this book the author thoroughly examines the basic mechanical and thermal effects of rotation, their influence on mass loss by stellar winds, the effects of differential rotation and its associated instabilities, the relation with magnetic fields and the evolution of the internal and surface rotation. Further, he discusses the numerous observational signatures of rotational effects obtained from spectroscopy and interferometric observations, as well as from chemical abundance determinations, helioseismology and asteroseismology, etc. On an introductory level, this book presents in a didactical way the basic concepts of stellar structure and evolution in "track 1" chapters. The other more specialized chapters form an advanced course on the graduate level and will further serve as a valuable reference work for professional astrophysicists.

It is clear that the discovery of solar eigenmodes and the resulting possibility of probing the solar interior is an event of primary importance for solar physics in general and for theories of the inner solar angular velocity in particular. While these theories are basic for the understanding of the solar spin down, differential rotation, dynamo and activity, they are however, extremely complex, and in all likelihood only limited further progress could have been achieved without the guidance of observations. Until recently and in spite of the scant observational basis the theoretical work has moved forward as the perusal of this book shows. There cannot be any doubt, however, that the present, rapidly expanding, worldwide observational program will lead ultimately to a vigorous theoretical development of the field. It appeared to the organizers that a meeting centered on theories of the inner solar angular velocity, comprising presentations of the main research areas by the involved scientists, would significantly foster this development since it would help to clarify the basic ideas of the subject. The meeting, held at the National Solar Observatory/Sacramento Peak, from August 11 to August 14, was the eighth in a series of summer symposia at Sacramento Peak. The unqualified success of the meeting could not have been possible without the unlim ited devotion of the staff at Sacramento Peak, Ray Smartt, Frank and Pat Hegwer, Ramona Elrod in particular.

Researchers specializing in pulsation, rotation, magnetic fields and stellar winds discuss O and B stars in papers from the October 1993 symposium in France, emphasizing that the various phenomena seen in these types of stars cannot be studied in isolation. Topics covered include line profile variations in Be stars, pulsation in rapidly rotating stars, ROSAT observations of B and Be stars, and time- dependent phenomena in OB star winds. Annotation copyright by Book News, Inc., Portland, OR

Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's. Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity. New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.

Stellar mass loss is an essential part of the cycling of material from the interstellar medium into stars and back, and must be understood if we are to model processes on galactic to cosmological scales. The study of stellar winds and the effects of stellar mass loss has reached a particularly exciting stage where observational capabilities are increasingly able to provide interesting constraints on models and theories. Recent resu1ts from theoretical and observational work for both hot and cool stars with substantial winds have led to the suggestion that a combination of pulsation with other mechanisms makes for particularly efficient mass loss from stars. This provided the original motivation for the organization of this workshop. The conference was organized along relatively conventional lines according to the types of objects being scrutinized. However the true unity of the proceedings comes from the interplay of the mechanisms involved. For example, for the cool, luminous Mira variables, pulsation leads to shock waves that extend the atmosphere, enhancing dust formation; radiation pressure on dust drives the wind, cooling the atmosphere and in some cases suppressing the shocks. Similarly for the Be stars, both pulsation (in this case, non-radial) and radiation pressure (due to UV resonance lines) are expected to be important, and this expectation is at least qualitatively borne out by the observations.

IAU Symposium 259 presents the first interdisciplinary, comprehensive review of the role of cosmic magnetic fields, involving astronomers and physicists from across the community. Offering both theoretical and observational topics ranging from Earth's habitability to the origin of the universe, this is an invaluable summary for researchers and graduate students.