Mass Losing Pulsating Stars And Their Circumstellar Matter

Editing the proceedings of a scientific meeting is not an easy task. Sometimes people who give an excellent talk do not send the manuscript by the deadline. However, this time, thanks to the punctuality of all the participants, we have this excellent volume for the workshop on mass losing pulsating stars and their circumstellar matter prepared in time. Almost all of the oral presentations including the summary are collected in this volume. We regret that we cannot put in this volume a few posters that we failed to receive before the editorial work. The workshop was planned as a small meeting with less than fifty attendants because the city of Sendai was far from the most of the active institutions. However, the number of submitted papers exceeded the SOC's expectation; many interesting contributions had to be scheduled in the poster session. Still, the oral sessions were so tight that many participants might have felt frustrated for the shortage of discussions. The organizers of the workshop have to apologize to the attendants for the inconvenience caused from such a happy underestimate about the size of the workshop.

In this Symposium, researchers specializing in pulsation, rotation, magnetic fields and stellar winds are brought together for the first time in order to broaden our understanding of O and B stars. Thanks to advances in digital spectroscopy, new types of pulsating B stars have been discovered. The pulsations can be understood in terms of the recent revision of metal opacities, but the effects of rapid rotation and magnetic fields need further study. Observations in the UV and X-ray regions demonstrate that many B and Be stars show other activity, besides pulsation which is not yet understood. The reason for the enhanced mass loss in Be stars is a question which dominates the Symposium and which remains unanswered, although it is surely to be found in activity at or near the photosphere coupled with rotation. It is shown that the geometry of the circumstellar envelopes around Be stars is indeed a flattened disk as they can now be optically resolved. The variability of radiatively-driven winds from O and B stars are likely related to the rotation of the star. This underlines the central theme of the book: that the various phenomena seen in these stars cannot be studied in isolation.

Stars are born and die in clouds of gas and dust, opaque to most types of radiation, but transparent in the infrared. Requiring complex detectors, space missions and cooled telescopes, infrared astronomy is the last branch of this discipline to come of age. After a very successful sky survey performed in the eighties by the IRAS satellite, the Infrared Space Observatory, in the nineties, brought spectacular advances in the understanding of the processes giving rise to powerful infrared emission by a great variety of celestial sources. Outstanding results have been obtained on the bright comet Hale-Bopp, and in particular of its water spectrum, as well as on the formation, chemistry and dynamics of planetary objects in the solar system. Ideas on the early stages of stellar formation and on the stellar initial mass function have been clarified. ISO is the first facility in space able to provide a systematic diagnosis of the physical phenomena and the chemistry in the close environment of pre-main sequence stars, in the interstellar medium, and in the final stages of stellar life, using, among other indicators, molecular hydrogen, ubiquitous crystalline silicates, water and ices. ISO has dramatically increased our ability to investigate the power production, excitation and fuelling mechanism of galaxies of every type, and has discovered a new very cold dust component in galaxies. ISO has demonstrated that luminous infrared galaxies were brighter and much more numerous in the past, and that they played a dominant role in shaping present day galaxies and in producing the cosmic infrared background.

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.

Planetary nebulae represent the brief transition between Asymptotic Giant Branch stars and White Dwarfs. As multi-wavelength laboratories they have played a key role in developing our understanding of atomic, molecular, dust and plasma processes in astrophysical environments. The means by which their wonderfully diverse morphologies are obtained is currently the subject of intense research, including hydrodynamical shaping mechanisms and the role of binarity, stellar magnetic fields and rotation. Their contribution to the chemical enrichment of galaxies is another very active research area, as is the ever growing use of their narrow high luminosity emission lines to probe the dynamics and mass distributions of galaxies and the intergalactic media of clusters of galaxies. IAU S234 summarises the current status of research on the properties and processes of planetary nebulae, as reported in reviews and papers by leading experts working in the field.

This complete guide and resource package for all amateur astronomers from novice to advanced comes with a CD-ROM packed with resources including light-curves and hundreds of star finder charts. The text also offers advice on telescopes and the use of CCD photometry.

This biography conveys the life and accomplishments of a Norwegian hero to the English speaking world, illustrating the beginnings of collaboration between science and industry. It shows how work in a small country laid the foundation for the green revolution.

It is good to mark the new Millennium by looking back as well as forward. Whatever Shines Should Be Observed looks to the nineteenth century to celebrate the achievements of five distinguished women, four of whom were born in Ireland while the fifth married into an Irish family, who made pioneering contributions to photography, microscopy, astronomy and astrophysics. The women featured came from either aristocratic or professional families. Thus, at first sight, they had many material advantages among their peers. In the ranks of the aristocracy there was often a great passion for learning, and the mansions in which these families lived contained libraries, technical equipment (microscopes and telescopes) and collections from the world of nature. More modest professional households of the time were rich in books, while activities such as observing the stars, collecting plants etc. typically formed an integral part of the children's education. To balance this it was the prevailing philosophy that boys could learn, in addition to basic subjects, mathematics, mechanics, physics, chemistry and classical languages, while girls were channelled into 'polite' subjects like music and needlework. This arrangement allowed boys to progress to University should they so wish, where a range of interesting career choices (including science and engineering) was open to them. Girls, on the other hand, usually received their education at home, often under the tutelage of a governess who would not herself had had any serious contact with scientific or technical subjects. In particular, progress to University was not during most of the nineteenth century an option for women, and access to scientific libraries and institutions was also prohibited. Although those women with aristocratic and professional backgrounds were in a materially privileged position and had an opportunity to 'see' through the activities of their male friends and relatives how professional scientific life was lived, to progress from their places in society to the professions required very special determination. Firstly, they had to individually acquire scientific and technical knowledge, as well as necessary laboratory methodology, without the advantage of formal training. Then, it was necessary to carve out a niche in a particular field, despite the special difficulties attending the publication of scientific books or articles by a woman. There was no easy road to science, or even any well worn track. To achieve recognition was a pioneering activity without discernible ground rules. With the hindsight of history, we recognise that the heroic efforts which the women featured in this volume made to overcome the social constraints that held them back from learning about, and participating in, scientific and technical subjects, had a consequence on a much broader canvas. In addition to what they each achieved professionally they contributed within society to a gradual erosion of those barriers raised against the participation of women in academic life, thereby assisting in allowing University places and professional opportunities to gradually become generally available. It is a privilege to salute and thank the wonderful women of the nineteenth century herein described for what they have contributed to the women of today. William Herschel's famous motto quicquid nitet notandum (whatever shines should be observed) applies in a particular way to the luminous quality of their individual lives, and those of us who presently observe their shining, as well as those who now wait in the wings of the coming centuries to emerge upon the scene, can each see a little further by their light.