Adaptive optics allows the theoretical limit of angular resolution to be achieved from a large telescope, despite the presence of turbulence. Thus an eight meter class telescope, such as one of the four in the Very Large Telescope operated by ESO in Chile, will in future be routinely capable of an angular resolution of almost 0.01 arcsec, compared tot he present resolution of about 0.5 arcsec for conventional imaging in good condition. All the world's major telescopes either have adaptive optics or are in the process of building AO systems. It turns out that a reasonable fraction of the sky can be observed using adaptive optics, with moderately good imaging quality, provided imaging in done in the near IR. To move out of the near IR, with its relatively poor angular resolution, astronomers need a laser guide star. There is a layer of Na atoms at approximately 90 km altitude that can be excited by a laser to produce such a source, or Rayleigh scattering can be employed lower in the atmosphere. But the production and use of laser guide stars is not trivial, and the key issues determining their successful implementation are discussed here, including the physics of the Na atom, the cone effect, tilt determination, sky coverage, and numerous potential astronomical applications.

It is only since recent years that the importance of the effects of outdoor lighting on the night-time environment and on the physical and mental health of humans is recognized on a wider scale. The related issue of light pollution is a particularly complex one, with potential conflicts of interest between the utilities, environmentalists, astronomers, the lighting industry and various government departments. Energy politics are always a sensitive issue, and light pollution is no exception to this rule.

The effects of light pollution on flora, fauna -including humans and their widely varying night-time activities- are often subtle and need extensive field studies to be quantified in a sensible manner.

The present conference, initiated by Commission 50 of the International Astronomical Union, is an attempt to bring together the astronomical community, the lighting industry, end-users, the utilities, and public authorities for a discussion and an exchange of ideas and information that will create goodwill among these groups and will thus contribute to making the global efforts to reduce pollution more efficient and effective.

Radio frequency pollution was also discussed in the context of radio astronomy and its efforts to create radio-quiet zones in collaboration with the government authorities that allocate frequency bands to the various users -mainly the telecommunications industry- and to protect the major planned and present radio observatories of the world.
The 3-day conference was attended by more than 130 representatives from 12 countries of all the above-mentioned groups, and a wide range of topics was discussed.

Some of the highlights were:
The presentationof the 1st world atlas of artificial night sky brightness (Cinzano et al.); the article by the International Darksky Association on their world-wide efforts to curb light pollution (Alvarez del Castillo et al.); the laws controlling light pollution implemented in Spain (Diaz et al.) and Chile (Sanhueza et al.), an overview of the work on radio frequency protection of sites (Cohen et al.) and the excellent introduction to the topic from the Chilean point of view (Daud).

Related topics in the book are light pollution education, aircraft contrails, space advertising (with an added document provided by the relevant UN commission), and an experiment on involving the population of an entire country in measuring sky brightness, by using the internet and the media.

The text is aimed at professionals from a wide range of disciplines related to lighting and its effects on the night-time environment in the broadest sense of the word. Lay persons interested in this emerging multi-disciplinary field can also find much of interest in this book.

Gamma-ray astronomy began in the mid-1960s with balloon satellite, and, at very high photon energies, also with ground-based instruments. However, the most significant progress was made in the last decade of the 20th century, when the tree satellite missions SIGMA, Compton, and Beppo-Sax gave a completely new picture of our Universe and made gamma-ray astronomy an integral part of astronomical research. This book, written by well-known experts, gives the first comprehensive presentation of this field of research, addressing both graduate students and researchers. Gamma-ray astronomy helps us to understand the most energetic processes and the most violent events in the Universe. After describing cosmic gamma-ray production and absorption, the instrumentation used in gamma-ray astronomy is explained. The main part of the book deals with astronomical results, including the somewhat surprising result that the gamma-ray sky is continuously changing.

A valuable reference for students and professionals in the field of deep space navigation

Drawing on fundamental principles and practices developed during decades of deep space exploration at the California Institute of Technology’s Jet Propulsion Laboratory (JPL), this book documents the formation of program Regres of JPL’s Orbit Determination Program (ODP). Program Regres calculates the computed values of observed quantities (e.g., Doppler and range observables) obtained at the tracking stations of the Deep Space Network, and also calculates media corrections for the computed values of the observable and partial derivatives of the computed values of the observables with respect to the solve-for-parameter vector-q. The ODP or any other program which uses its formulation can be used to navigate a spacecraft anywhere in the solar system.

A publication of the JPL Deep Space Communications and Navigation System Center of Excellence (DESCANSO), Formulation for Observed and Computed Values of Deep Space Network Data Types for Navigation is an invaluable resource for graduate students of celestial mechanics or astrodynamics because it:

• features the expertise of today’s top scientists
• places the entire program Regres formulation in an easy-to-access resource
• describes technology which will be used in the next generation of navigation software currently under development

The Deep Space Communications and Navigation Series is authored by scientists and engineers with extensive experience in astronautics, communications, and related fields. It lays the foundation for innovation in the areas of deep space navigation and communications by conveying state-of-the-art knowledge in key technologies.

The book reviews methods for the numerical and statistical analysis of astronomical datasets with particular emphasis on the very large databases that arise from both existing and forthcoming projects, as well as current large-scale computer simulation studies. Leading experts give overviews of cutting-edge methods applicable in the area of astronomical data mining. Case studies demonstrate the interplay between these techniques and interesting astronomical problems. The book demonstrates specific new methods for storing, accessing, reducing, analysing, describing and visualising astronomical data which are necessary to fully exploit its potential.

IAU Colloquium 165, Dynamics and Astrometry of Natural and Artificial Celestial Bodies, was held in Poznan, Poland, in July 1996, bringing together over 200 scientists from 27 countries who discussed their work in 179 oral and poster presentations. The present volume contains 83 of the papers presented at the meeting. The meeting brought together specialists from diverse fields who focused on the very close collaboration between dynamics and astrometry, where one discipline contributes to the progress of the other. The oral sessions were organized into general categories pertaining to: solar system dynamics; new observational techniques, catalogues, and astrometry; dynamics and observational problems of artificial satellites and space debris; rotation of solar system objects; reference systems and astronomical standards; new mathematical techniques; and three all-day poster sessions. This volume is divided into seven parts, comprising 83 contributions, a list of participants and an index.

The idea for another conference on the theme of Infrared Astronomy with Arrays actually goes back to March 1987. At a party held in my home at the end of the Hilo conference, excitement was running high and everyone present was in favor of another meeting. I recall suggesting to Al Fowler that the next meeting could be in Tucson. Despite Al's reply to the effect that Hawaii was a much nicer location, a meeting was held in Tucson three years later. That meeting focussed more on the astrophysics which had been accomplished with the detectors, rather than on techniques and methods. However, it was already apparent in February of 1990 that a new generation of larger m arrays would soon supersede the 64x64 class of devices and so, having just moved from the UK Infrared Telescope unit in Hawaii to join with Eric Becklin in his move to UCLA, it seemed to me that another Hilo-style conference was appropriate, and Eric agreed.

H.T. MacGilLIVRAY Royal Observatory Blackford Hill Edinburgh EH9 3HJ Scotland U.K. lAU Symposium No. 161 on 'Astronomy from Wide-Field Imaging', held in Potsdam, Germany, during 23-27th August 1993, was the first conference organised by the recently-formed Working Group of lAU Commission 9 on 'Wide-Field Imaging'. This Working Group was instigated during the XXIst meeting of the General Assembly of the International Astronomical Union in Buenos Aires in 1991, and represented a merging of the former formal lAU Working Group on 'Astronomical Photography' and the informal 'Digitised Optical Sky Surveys' Working Group. Dr. Richard West was 'invited' to be Chairperson, and hence was given the daunting task of organising the Group from scratch. The very fact that the first conference after only two years was a major lAU Symposium says much about the determination and enthusiasm of Richard West to fulfilling the aims of the new Working Group. The siting of the conference in Potsdam in formerly East Germany provided an excellent opportunity to advantage from the political changes in Eastern Europe. Good access to the meeting was possible by scientists from Eastern European countries, allowing exchange of information on the very important Wide-Field facilities in both East and West, information on the rich archives of photographic plates that exist in both East and West, and allowing discussions between scientists facing very similar problems in both East and West.

The History of Astronomy in the Orient has been vigorously researched in the last several decades. We may recall here the publications of Joseph Needham's monumental volumes on Science and Civilisation in China, one volume of which is devoted to Chinese Astron- omy, S. Nakayama's A History of Japanese Astronomy (Tokyo, 1969), and the School of Edward Kennedy's writings on Islamic Astronomy,1 which particularly culminated in the studies of the Critique of Ptolemaic Astronomy by the Islamic astronomers belong- ing to Na~lruddin rusI's School, established at Maragha Observatory during the l3-l4th 2 centuries. In this backdrop of the emphasis on astronomy in the Orient, the first IAU Colloquium (No.9 1 ) on "History of Oriental Astronomy" was organised during the IAU General Assem- bly, held in New Delhi, Nov. 13-16, 1985. The Proceedings ofthe Colloquium were then 3 published. The second effort by this Commission was to organise another International Colloquium on Interaction of European and Asian Astronomy, held in Vienna in Sept. 4 1990. Unfortunately its Proceedings could not be published. Noteworthy is that the Far East or the East Asia did not lag behind in this endeavour.

It is rare for a complete biography of an Australian scientist, particularly of an Australian woman scientist, to be published. It is rarer for such a book to be co-authored by an American. Although scientists have written discourses on the history of their discipline, it is most unusual for a scientist to write a full length biography of a colleague in his ?eld. It is also uncommon for a man to write about an Australian woman scientist; most of the work on Australian women scientists has been done by other women. However, these authors, both distinguished researchers in the ?eld of radio astr- omy, became so interested in the history of their discipline and in the career of the pioneer radio astronomer Ruby Payne-Scott that they spent some years bringing this book to fruition. Until relatively recently, Ruby Payne-Scott had been the only woman scientist mentioned brie?y in histories of Australian science or of Australian radio astronomy. This book will be an invaluable resource for anyone interested in these disciplines. Being scientists themselves, the authors explain Payne-Scott's scienti?c work in detail; therefore, the value and importance of her contributions can, for the ?rst time, be recognised, not only by historians but also by scientists.

Gravitational lensing is by now sufficiently well understood that it can be used as a tool of investigation in other astrophysical areas. Applications include the determination of the Hubble constant, probing the dark matter context of galaxies and the mapping of the universe to the identification of otherwise invisible large-scale structures. Each chapter of the book covers in a self-contained manner a subfield of gravitational lensing, with the double aim of describing in a simple way the basics of the theory and of reviewing the most recent developments as well as applications foreseen in the near future. The book will thus be particularly useful as a high-level textbook for nonspecialist researchers and advanced students wishing to become familiar with the field all the way up to the forefront of research.

This volume is concerned essentially with the modern developments in reflecting telescope optics. In the last twenty years, modern technology has revolutionized not only manufacturing and test procedures but also the whole area of quality specification with the introduction of active control into the functioning telescope. Other subjects covered here are alignment of telescope optics, atmospheric optics, including adaptive optics, reflecting coatings and ancillary equipment (adapters and baffles). Although an independent work, Vol. II is heavily cross-referenced with Vol. I. It is richly illustrated and gives, together with Vol. I, the most complete list of references available; it can also therefore be regarded as a source book.

Digital sky surveys, data from orbiting telescopes, and advances in computation have increased the quantity and quality of astronomical data by several orders of magnitude in recent years. Making sense of this wealth of data requires sophisticated statistical and data analytic techniques. Fortunately, statistical methodologies have similarly made great strides in recent years. Powerful synergies thus emerge when astronomers and statisticians join in examining astrostatistical problems and approaches. The volume focuses on several themes: · The increasing power of Bayesian approaches to modeling astronomical data · The growth of enormous databases, leading an emerging federated Virtual Observatory, and their impact on modern astronomical research · Statistical modeling of critical datasets, such as galaxy clustering and fluctuations in the microwave background radiation, leading to a new era of precision cosmology · Methodologies for uncovering clusters and patterns in multivariate data · The characterization of multiscale patterns in imaging and time series data As in earlier volumes in this series, research contributions discussing topics in one field are joined with commentary from scholars in the other. Short contributed papers covering dozens of astrostatistical topics are also included.

This volume contains a comprehensive treatment of X-ray spectroscopy, as applied in astrophysics. It is presented in the form of extensive notes of lectures given by seven distinguished scientists at the Tenth Summer School of the European Astrophysics Doctoral Network. The subjects covered are: basic line and continuum radiation processes in X-ray and gamma-ray astronomy; atomic physics of collision- and radiation-dominated plasmas; X-ray spectroscopic observations with ASCA and BeppoSAX; future X-ray spectroscopy missions; X-ray optics, and X-ray spectroscopy instrumentation. The book, which will appeal to both researchers and graduate students, is timely in view of the scheduled launches of the big X-ray observatories AXAF and XMM in 1999.

"If you buy just one guide...you won't do better than this" - BBC Sky at Night Magazine "I will continue to enjoy 'Philip's Stargazing' as the months go by" - Helen Sharman, Astronaut "Very useful indeed" - Chris Lintott, Sky at Night presenter Discover the latest in stargazing with the new and definitive guide to the night sky. Whether you're a seasoned astronomer or just starting out, Philip's Stargazing 2022 is the only book you'll need. Compiled by experts and specially designed for use in Britain and Ireland, Stargazing 2022 acts as a handily illustrated and comprehensive companion. - 12 Brand-New Maps for year-round astronomical discovery - Month-to-Month information. Daily Moon Phase Calendar, highlighting special lunar events throughout the year - Planet Watch for ideal viewing days in 2022 - Avoid light pollution with our detailed Dark Sky Map - Expert advice and insight throughout from internationally renowned Professor Nigel Henbest - A 'Behind the Scenes' look at astrophotography from expert Robin Scagell - Complete calendar of major astronomical events, including the Top 20 Sky Sights of 2022 - Jargon Buster, explaining common or confusing terms - The planets' movements explained from solar and lunar eclipses to meteor showers and comets

A small country builds a world-class telescope in its backyard and lives happily ever after (or at least for a quarter century). That in a nutshell is the story told in this collection of essays. The country of course is the Netherlands, and the telescope is the Westerbork Synthesis Radio Tele scope (WSRT), brainchild of Jan Oort. Living happily in this context is a continuing record of discovery and as such also a continuing basis for se curing observing time on facilities in other countries and operating at other frequencies. As our community celebrates the Silver Anniversary of the radio tele scope at Westerbork, it is fitting that we pause to take account of the scientific discoveries and insights it made possible. Initially the instrument represented the very significant step away from university-run, specialist facilities to a well-supported, common-user radio imager also having spec tral and polarization capabilities. It pioneered the mode of operation now common for satellite observatories, in which data is taken and calibrated by technicians and provided to researchers ready for analysis. It has been a major source of discovery in, among other areas, research on neutral hy drogen and studies of dark matter in galaxies.

Many important observational clues about our understanding of how stars and planets form in the interior of molecular clouds have been amassed using recent technological developments. ESO's very large telescope promises to be a major step forward in the investigation of stellar nurseries and infant stars. This volume collects papers from the leaders in this very timely field of astrophysical research. It presents theoretical and a host of observational results and many papers show the plans for future observations.

Intended for nonspecialists with some knowledge of physics or engineering, The Quantum Beat covers a wide range of salient topics relevant to atomic clocks, treated in a broad intuitive manner with a minimum of mathematical formalism. Detailed descriptions are given of the design principles of the rubidium, cesium, hydrogen maser, and mercury ion standards; the revolutionary changes that the advent of the laser has made possible, such as laser cooling, optical pumping, the formation of optical molasses, and the cesium fountain standard; and the time-based global navigation systems, Loran-C and the Global Positioning System. Also included are topics that bear on the precision and absolute accuracy of standards, such as noise, resonance line shape, the relativistic Doppler effect as well as more general relativistic notions of time relevant to synchronization of remote clocks, and time reversal symmetry. the development of atomic clocks in the first edition, but brings up to date the extraordinary developments in recent years, culminating in clocks based on quantum resonance at optical frequency in individual ions confined in miniature electromagnetic traps. These, together with advances in the generation of wide-band coherent frequency combs spanning the spectrum as far as the optical range, has made possible the direct measurement of phenomena occurring at optical frequencies As a result of these recent advances, in addition to the time-based GPS and LORAN C navigation systems treated in the first edition, other important applications of a fundamental scientific interest have become feasible. These include satellite-borne tests of the theory of general relativity and the equivalence principle on which it is based.

The imaging process in stellar interferometers is explained starting from first principles on wave propagation and diffraction. Wave propagation through turbulence is described in detail using Kolmogorov statistics. The impact of turbulence on the imaging process is discussed both for single telescopes and for interferometers. Correction methods (adaptive optics and fringe tracking) are presented including wavefront sensing/fringe sensing methods and closed loop operation. Instrumental techniques like beam combination and visibility measurements (modulus and phase) as well as Nulling and heterodyne interferometry are described. The book closes with examples of observing programmes linking the theory with individual astrophysical programmes.

Astrophysics is facing challenging aims such as deep cosmology at redshift higher than 10 to constrain cosmology models, or the detection of exoplanets, and possibly terrestrial exoplanets, and several others. It requires unprecedented ambitious R&D programs, which have definitely to rely on a tight cooperation between astrophysics and optics communities. The book addresses most of the most critical interdisciplinary domains where they interact, or where they will do. A first need is to collect more light, i.e. telescopes still larger than the current 8-10 meter class ones. Decametric, and even hectometric, optical (from UV to IR wavelengths) telescopes are being studied. Whereas up to now the light collecting surface of new telescopes was approximately 4 times that of the previous generation, now this factor is growing to 10 to 100. This quantum leap urges to implement new methods or technologies developed in the optics community, both in academic labs and in the industry. Given the astrophysical goals and technological constraints, new generation adaptive optics with a huge number of actuators and laser guide stars devices have to be developed, from theoretical bases to experimental works. Two other newcomers in observational astrophysics are interferometric arrays of optical telescopes and gravitational wave detectors. Up-to-date reviews of detectors and of spectrographs are given, as well as forefront R&D in the field of optical coatings and of guided optics. Possible new ways to handle photons are also addressed, based on quantum physics. More and more signal processing algorithms are a part and parcel of any modern instrumentation. Thus finally the book gives two reviews about wavefront processing and about image restoration and deconvolution algorithms for ill conditioned cases.

A personal account of the evolution of millimeter-wave astronomy at the US National Radio Astronomy Observatory. The author recounts the behind-the-scenes activities of the staff from the beginnings at Kitt Peak to the closing of the Tuscon offices.

Radio techniques were the nrst to lead astronomy away from the quiescent and limited Universe revealed by traditional observations at optical wave lengths. In the earliest days of radio astronomy, a handful of radio physicists and engineers made one startling discovery after another as they opened up the radio sky. With this collection of classic papers and the extensive intro ductory material, the reader can experience these exciting discoveries, as well as understand the developing techniques and follow the motivations which prompted the various lines of inquiry. For instance he or she will follow in detail the several attempts to detect radio waves from the sun at the turn of the century; the unravelling by Jansky of a "steady hiss type static"; the incredible story of Reber who built a 9 meter dish in his backyard in 1937 and then mapped the Milky Way; the vital discoveries by Hey and colleagues of radio bursts from the Sun and of a discrete source in the constellation of Cygnus; the development of receivers and interferometry in the post-war years by the groups led by Ryle in Cambridge and Pawsey in Sydney; the nrst measurements and exciting identiftcations of Taurus A (the Crab Nebula), Centaurus A, Virgo A, Cassiopeia A, and Cygnus A, the last opening the neld of radio cosmology; the early development of synchroton theory; and the prediction and discovery seven years later of the 21 cm line of neutral hy drogen."

Celestial fundamental catalogues are a prerequisite for the determination of absolute positions and motions in space. Presently, positional astrometry is at the watershed between classical fundamental catalogues, based on moving reference stars, and modern catalogues, based on extragalactic reference objects with non-measurable motion. This book addresses the concepts and methods of the respective construction techniques leading to the stellar frame of the FK5 (fifth fundamental catalogue) and to the newly adopted extragalactic radio reference frame, ICRF (international celestial reference frame), with its extension to optical wavelengths by the Hipparcos Catalogue. While principal outlines of meridian circle observations are given, emphasis is put in some detail on the VLBI technique as applied to astrometry, and to the observational techniques used in the Hipparcos mission, including the tie of the originally non-anchored rigid Hipparcos sphere into the ICRF.

th The 4 ESO CCO Workshop, Optical Detectors for Astronomy, was held during September 13-16, 1999 at its usual location, the headquarters of the European Southern Observatory in Garching, Germany. We prefer to remember this workshop as a "meeting of friends," who came to Garching to visit ESO and to present their work, rather than a formal meeting. Based on our experience with the 1996 ESO CCO workshop, we deliberately put emphasis on creating an environment that encouraged the participants to stay together and informally exchange ideas. These informal events began with a tour of the BWM auto factory and continued with a reception at "SchloB Beletic," the conference dinner at a real SchloB of the Bavarian International School (where the participants enjoyed basket, baseball, table soccer, rock climbing and eventually dancing) and concluded with a tour of the Paulaner Brewery and dinner at the Seehaus in the Englisher Garten. The lunch "Biergarten," adjacent to the poster session area, was a daily meeting point. The result was a good mixture of excellent presentations and posters, collected in these Proceedings, and many occasions for people to get in touch and to have fun together, as witnessed by the selection of workshop pictures that we randomly placed between papers. This book contains a special contribution.