State-of-the-art review of the growing field of astrometry, for researchers and graduate students.

A complete record of the formal organisational and administrative proceedings of the XXVII General Assembly of the International Astronomical Union.

The Proceedings of IAU S248 reflect the state-of-the-art in the field of astrometry, summarizing the scientific achievements at the tenth anniversary of the Hipparcos and Tycho Catalogue release. It shows the latest achievements in ground-based astrometry and details the progress of second-generation astrometric satellites. Currently, the highest accuracies at a micro-arc-second level are reached by interferometric techniques, especially at radio wavelengths. Establishing and maintaining the celestial reference frame at this level, within a relativistic framework, has been identified as one of astrometry's main tasks. The era of large surveys and virtual observatories brings inevitable changes to the role of astrometry in astronomy. For instance, galactic structure and evolution can be fully understood only by combining astrometric and astrophysical parameters. Finally, due attention is given to astrometric education in astronomy curricula for the twenty-first century. These Proceedings convincingly demonstrate the ever growing role played by astrometry in understanding the Universe.

Astrometry encompasses all that is necessary to provide the positions and motions of celestial bodies. This includes observational techniques, instrumentation, processing and analysis of observational data, reference systems and frames, and the resulting astronomical phenomena. Astrometry is fundamental to all other fields of astronomy, from the pointing of telescopes, to navigation and guidance systems, to distance and motion determinations for astrophysics. In the last few decades, new observational techniques have enabled improvements in accuracy by orders of magnitude. Starting from basic principles, this book provides the fundamentals for this new astrometry at milli- and micro-arcsecond accuracies. Topics include: basics of general relativity; co-ordinate systems; vectors, tensors, quaternions, and observational uncertainties; determination and use of the celestial and terrestrial reference systems and frames; applications of new observational techniques; present and future star catalogues and double star astrometry. This comprehensive reference will be invaluable for graduate students and research astronomers.

A complete and in-depth review of exoplanet research, covering the discovery methods, physics and theoretical background.

From prehistoric times, mankind has looked up at the night sky, and puzzled at the changing positions of the stars. How far away they are is a question that has confounded scientists for centuries. Over the last few hundred years, many scientific careers – and considerable resources – have been devoted to measuring their positions and motions with ever increasing accuracy. And in the last two decades of the 20th century, the European Space Agency developed and launched the Hipparcos satellite, around which this account revolves, to carry out these exacting measurements from space. What has prompted these remarkable developments? Why have governments been persuaded to fund them? What are scientists learning from astronomy's equivalent of the Human Genome Project? This book traces the subject's history, explains why such enormous efforts are considered worthwhile, and interweaves these with a first-hand insight into the Hipparcos project, and how big science is conducted at an international level. The involvement of amateur astronomers, and the Hipparcos contributions to climate research, ‘death stars' passing close to the Sun, and the search for extra-solar planets and even intelligent life itself, are some of the surprising facets of this unusual space mission.