Astrometry is on the threshold of great changes due to the fact that this decade, alone, is witnessing an improvement of stellar positions equivalent to the total improvement of the previous two centuries. The Hipparcos Satellite has concluded its observations, and the catalog is in preparation. Preliminary results assure that the Hipparcos catalog will provide positions, parallaxes and annual proper motions for over 100,000 stars with accuracies of 1.5 milliarcseconds. In addition, the Tycho catalog will provide positions of about 30 milliarcseconds accuracy for over 1 million stars, and annual proper motions with 3 milliarcsecond accuracy will subsequently be ob tained by means of first epoch positions from the Astrographic Catalog. Optical interferometers on the ground are beginning operation, and these instruments can provide observational accuracies of approximately one milliarcsecond. Also, the traditional reference frame based on the Fun damental Catalog of bright stars is being replaced by the extragalactic ref erence frame, based on radio sources with accuracies of one milliarcsecond. Thus, astrometry will change from a fundamental reference frame defined in terms of the dynamical reference frame of the solar system with accuracies of 100 milliarcseconds to a space-fixed, extragalactic reference frame with accuracies of one milliarcsecond. Future astrometric observations should be in the 1 -100 milliarcsecond accuracy range. There are a number of concepts for future astrometric instruments in space. Most of these can provide sub-milliarcsecond astrometric accuracies."

This is the latest effort in a sequence of presentations begun in 1949 with a series of lectures on long-focus photographic astrometry given by the author as Fulbright professor in Paris at the invitation by the late H. Mineur, at that time Director of the Institut d' Astrophysique. These earlier lectures were published as a series of review articles in Popular Astronomy (1951) and appeared both as Contributions de l'Institut d'Astrophysique, Serie A, No. 81 and as reprint No. 75 of Sproul Observatory. A more elaborate presenta tion was given in 1963 in Stars and Stellar Systems, which was followed by Principles of Astrometry (1967, W. H. Freeman & Co.). During the second half of 1974, again under Fulbright auspices, at the invitation of Pik Sin The, I lectured at the Astronomical Institute in Amster dam, followed by a short course in May-June 1978 at the invitation of E. P. J. van den Heuvel. I gave a more extensive course at the Institut d' As trophysique at the invitation of J. C. Pecker of the College de France and of J. Audouze, Director of the LA.P. Both in Amsterdam and in Paris I had presented occasional astrometric topics at various times. The opportunity to lecture in France and in Holland has facilitated, influenced and improved the organization and contents of the presentations on the subject of long-focus photographic astrometry."

IAU Transactions XXIIB summarizes the work of the XXIInd General Assembly. The discourses given during the Inaugural and Closing Ceremonies are reproduced in Chapters I and III, respectively. The proceedings of the two sessions of the General Assembly will be found in Chapter II, which includes the Resolutions and the report of the Finance Committee. The Statutes, Bye-Laws and a few working rules of the Union are published in Chapter IV. The Accounts and other aspects of the administration of the Union are recorded in Chapter V, together with the report of the Executive Committee for this last triennium, and provide the permanent record for the Union in the period 1991-1994. This volume also contains the Commission reports from The Hague compiled by the Presidents of the Commissions (Chapter VI). Finally, Chapter VII contains the list of countries adhering to the Union and the alphabetical, geographical and commission membership lists of about 8000 individual members. The IAU still appears to be unique among the scientific Unions in maintaining this category of individual membership which contributes in a crucial way to the spirit and the aims of the Union.

Active Galactic Nuclei radiate over the electro-magnetic spectrum from radio waves to gamma rays. Understanding the physics of these objects therefore requires the synthesis of results from many different domains of Astronomy. It was the aim of the conference "Active Galactic Nuclei across the Electromagnetic Spectrum" to provide a forum where this exchange could take place. Some 300 astronomers participated to the conference, 250 of them presented results either as oral papers or in the form of posters. Observations in all domains of the electro magnetic spectrum in which astronomical observations can be made from the ground or from space were presented. Many theoretical contributions were also given. There has been a tremendous growth in the number and quality of Astronomical obser vations in many spectral domains over the past several years. Students of Active Galactic Nuclei have been particularly keen to make use of the available facilities (both space born and on the ground), often in a very organised way, in order to obtain repeated simultane ous data covering large bands of the spectrum. This approach has produced a qualitatively new set of data for understanding the physics of Active Galactic Nuclei. The task of the meeting was to review this data in a coherent way."

This volume provides an overview of the field of Astrostatistics understood as the sub-discipline dedicated to the statistical analysis of astronomical data. It presents examples of the application of the various methodologies now available to current open issues in astronomical research. The technical aspects related to the scientific analysis of the upcoming petabyte-scale databases are emphasized given the importance that scalable Knowledge Discovery techniques will have for the full exploitation of these databases. Based on the 2011 Astrostatistics and Data Mining in Large Astronomical Databases conference and school, this volume gathers examples of the work by leading authors in the areas of Astrophysics and Statistics, including a significant contribution from the various teams that prepared for the processing and analysis of the Gaia data.

"Meteoric phenomena" is the accepted term for the complex of physi cal phenomena that accompany the entry of meteoric bodies into the at mosphere of the earth (or of any planet). "Meteoric bodies" are usually defined as cosmic bodies observed by optical or radar techniques, when they enter the atmosphere. The limiting sensitivity of present-day radar equipment makes it possible to record meteors of up to stellar magnitude +14, while the most brilliant bolides may reach magnitude -19. On a mass 7 7 scale this corresponds approximately to a range of 10- to 10 g. How ever, met or astronomy is also concerned with larger objects, namely crater-forming meteorites, or objects that cause large-scale destruction when they arrive through the atmosphere (an example is the Tunguska River meteorite). Consideration of the interaction of such objects with 12 the terrestrial atmosphere extends the mass range to 10 g. On the other hand, scientists studying fragmentation processes in meteoric bod 7 ies have to consider particles with masses less than 10- g, and the use of data from meteoric-particle counters on rockets and artificial satel lites, from microcraters on the lunar surface, and from noctilucent clouds 12 lowers the minimum mass to 10- g. Therefore, the mass range of meteoric bodies, or meteoroids, encompasses 24 orders of magnitude. Although recent years have witnessed considerable development in meteor research, both in the Soviet Union and elsewhere, the main mono graphs on meteor physics were published twenty or more years ago."

IAU Symposium 135 on Interstellar Dust was hosted and co-sponsored by NASA's Ames Research Center from July 26-30, 1988. The symposium was held at the lovely campus of Santa Clara University situated around the historic Santa Clara Mission in California. The meeting was made possible by generous grants from the Astron omy and Relativity Branch of the National Aeronautics and Space Administration and the Galactic Astronomy Program of the National Science Foundation. The International Astronomical Union provided travel grants to a few participants from countries with limited travel funds. We are particularly grateful for the support and services rendered by the dedicated staff at NASA's Ames Research Center and to the" SET! Institute for professionally and expeditiously administering the U.S. grants. This symposium brought together 199 scientists representing 19 different coun tries. The wide range of interest and expertise of the participants - all in some way related to interstellar dust - is reflected in the great variety of topics that were discussed during the symposium ranging from UV, visible and IR observations of interstellar extinction to quantum-statistical calculations of the IR emission from highly vibrationally excited molecules. During the course of the meeting, 41 invited review papers and 140 contributed papers were presented. This book is a collection of the invited review papers. The contributed papers have been published in a companion volume, NASA CP-3036, available from National Technical Information Service, Springfield, Virginia 22161, USA.

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.

The scope of the book is to give an overview of the history of astroparticle physics, starting with the discovery of cosmic rays (Victor Hess, 1912) and its background (X-ray, radioactivity).
The book focusses on the ways in which physics changes in the course of this history. The following changes run parallel, overlap, and/or interact:
- Discovery of effects like X-rays, radioactivity, cosmic rays, new particles but also progress through non-discoveries (monopoles) etc.
- The change of the description of nature in physics, as consequence of new theoretical questions at the beginning of the 20th century, giving rise to quantum physics, relativity, etc.
- The change of experimental methods, cooperations, disciplinary divisions.
With regard to the latter change, a main topic of the book is to make the specific multi-diciplinary features of astroparticle physics clear."

The book presents the most recent developments of laboratory studies in astrophysics and space research. The individual chapters review laboratory investigations under simulated space conditions, studies for the design of successful space experiments or for supporting the interpretation of astronomical and space mission recorded data. Related theoretical models, numerical simulations and in situ observations demonstrate the necessity of experimental work on the Earth's surface. The expertise of the contributing scientists covers a broad spectrum and is included in general overviews from fundamental science to recent space technology. The book intends to serve as a reference for researchers and graduate students on the most recent activities and results in laboratory astrophysics, and to give reviews of their applications in astronomy, planetology, cosmochemistry, space research and Solar System exploration.

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.

IAU Transactions are published as a volume corresponding to each General Assembly. Volume A is produced prior to the Assembly and contains Reports on Astronomy, prepared by each Commission President. The intention is to summarize the astronomical results that have affected the work of the Commission since the production of the previous Reports up to a time which is about one year prior to the General Assembly. Volume B is produced after the Assembly and contains accounts of Commission Meetings which were held, together with other material. The reports included in the present volume range from outline summaries to lengthy compilations and references. Most reports are in English.

Written by active research scientists who study the volcanism of Earth and of other planets, the contributions provide the first general review of volcanic activity throughout the Solar System. Successive chapters describe past and present volcanic activity as it is observed throughout the Solar System. These chapters relate to readers not only our present knowledge of volcanism throughout the Solar System but also how frontline scientists working in this field conduct their research.

Quantum physics may appear complicated, especially if one forgets the "big picture" and gets lost in the details. However, it can become clearer and less tangled if one applies a few fundamental concepts so that simplified approaches can emerge and estimated orders of magnitude become clear. Povh and Rosina's Scattering and Structures presents the properties of quantum systems (elementary particles, nucleons, atoms, molecules, quantum gases, quantum liquids, stars, and early universe) with the help of elementary concepts and analogies between these seemingly different systems. In this new edition, sections on quantum gases and an up to date overview of elementary particles have been added.

Many new tests of gravity and, in particular, of Einstein's general relativity theory will be carried out in the near future: The Lense--Thirring effect and the equivalence principle will be tested in space; moreover, gravitational waves will be detected, and new atomic interferometers and clocks will be built for measurements in gravitational and inertial fields. New high-precision devices have made these experiments feasible. They will contribute to a better understanding of gravitational physics. Both experimental developments and the theoretical concepts are collected in this volume. Exhaustive reviews give an overall insight into the subject of experimental gravitation.

This volume is the documentation of the first Course on 'Neutron Stars, Active Galactic Nuclei and Jets', of an Erice School with a wide astro physical scope. The choice of the subject was made because of an apparent similari ty - stressed already at earlier meetings - of four classes of astrophy sical jet sources: Active Galactic Nuclei, Young Stellar Objects, Binary Neutron Stars and Binary White Dwarfs. They share important properties such as their morphology, high variability and large veloci ty gradients as well as - with some inference - their broad spectrum, hypersonic outflow and core/lobe power ratio. Despite this apparent similarity of the four source classes, quite different models have been put forward for their description: (i) The central engine of active galactic nuclei has been generally thought to be a black hole, in contrast to the central engine of young stellar objects and cometary nebulae which apparently is a pre-T-Tauri star, some six orders of magnitude less compact, and to the central engine of planetary nebulae which mayor may not be a binary white dwarf. (ii) The elongated lobes, or flow patterns, have been often interpreted as highly directional stellar wind outflows whereas in a few well mapped cases, the elongated flow appears to be 'pumped up' through a much narrower channel, or jet, both in the extragalactic and stellar sources."

The 2005 meeting in Taormina, Italy was attended by 127 professionals who develop and use the highest quality detectors for wavelengths from x-ray to sub-mm, with emphasis on optical and infrared detectors. The meeting consisted of overview talks, technical presentations, poster sessions and roundtable discussions. These proceedings capture the technical content and the spirit of the 2005 workshop. The 87 papers cover a wide range of detector technologies including CCDs, CMOS, APDs, and sub-mm detectors. There are papers on observatory status and plans, special applications, detector testing and characterization, and electronics. A special feature of these proceedings is the inclusion of pedagogical overview papers, which were written by teams of leading experts from different institutions. These proceedings are appropriate for a range of expertise levels, from undergraduates to professionals working in the field. The information presented in this book will serve as a valuable reference for many years to come. This workshop was organized by the Scientific Workshop Factory, Inc. and the INAF- Osservatorio Astrofisico di Catania.

This volume contains five articles describing the mission and its instruments. The first paper, by the project scientist Richard C. Elphic and his colleagues, describes the mission objectives, the launch vehicle, spacecraft and the mission itself. This is followed by a description of LADEE's Neutral Mass Spectrometer by Paul Mahaffy and company. This paper describes the investigation that directly targets the lunar exosphere, which can also be explored optically in the ultraviolet. In the following article Anthony Colaprete describes LADEE's Ultraviolet and Visible Spectrometer that operated from 230 nm to 810 nm scanning the atmosphere just above the surface. Not only is there atmosphere but there is also dust that putatively can be levitated above the surface, possibly by electric fields on the Moon's surface. Mihaly Horanyi leads this investigation, called the Lunar Dust Experiment, aimed at understanding the purported observations of levitated dust. This experiment was also very successful, but in this case their discovery was not the electrostatic levitation of dust, but that the dust was raised by meteoroid impacts. This is not what had been expected but clearly is the explanation that best fits the data. Originally published in Space Science Reviews, Volume 185, Issue 1-4, 2014.

Roger Penrose, one of the most accomplished scientists of our time, presents the only comprehensive and comprehensible account of the physics of the universe. From the very first attempts by the Greeks to grapple with the complexities of our known world to the latest application of infinity in physics, "The Road to Reality" carefully explores the movement of the smallest atomic particles and reaches into the vastness of intergalactic space. Here, Penrose examines the mathematical foundations of the physical universe, exposing the underlying beauty of physics and giving us one the most important works in modern science writing.

A treasure for anyone interested in early modern India and the history of mathematics, this first English translation of the Siddhantasundara reveals the fascinating work of the scholar-astronomer Jnanaraja (circa 1500 C.E.). Toke Lindegaard Knudsen begins with an introduction to the traditions of ancient Hindu astronomy and describes what is known of Jnanaraja's life and family. He translates the Sanskrit verses into English and offers expert commentary on the style and substance of Jnanaraja's treatise.

The Siddhantasundara contains a comprehensive exposition of the system of Indian astronomy, including how to compute planetary positions and eclipses. It also explores deep, probing questions about the workings of the universe and sacred Hindu traditions. In a philosophical discussion, the treatise seeks a synthesis between the cosmological model used by the Indian astronomical tradition and the cosmology of a class of texts sacred in Hinduism. In his discourse, which includes a discussion of the direction of down and adhesive antipodeans, Jnanaraja rejects certain principles from the astronomical tradition and reinterprets principles from the sacred texts. He also constructs a complex poem on the seasons, many verses of which have two layers of meaning, one describing a season, the other a god's activities in that season.

The Siddhantasundara is the last major treatise of Indian astronomy and cosmology to receive serious scholarly attention, Knudsen's careful effort unveils the 500-year-old Sanskrit verses and shows the clever quirkiness of Jnanaraja's writing style, his keen use of mathematics, and his subtle philosophical arguments.

This book is a historical-epistemological study of one of the most consequential breakthroughs in the history of celestial mechanics: Robert Hooke's (1635-1703) proposal to "compoun[d] the celestial motions of the planets of a direct motion by the tangent & an attractive motion towards a centrat body" (Newton, The Correspondence li, 297. Henceforth: Correspondence). This is the challenge Hooke presented to Isaac Newton (1642-1727) in a short but intense correspondence in the winter of 1679-80, which set Newton on course for his 1687 Principia, transforming the very concept of "the planetary heavens" in the process (Herivel, 301: De Motu, Version III). 1 It is difficult to overstate the novelty of Hooke 's Programme * The celestial motions, it suggested, those proverbial symbols of stability and immutability, werein fact a process of continuous change: a deflection of the planets from original rectilinear paths by "a centraU attractive power" (Correspondence, li, 313). There was nothing necessary or essential in the shape of planetary orbits. Already known to be "not circular nor concentricall" (ibid. ), Hooke claimed that these apparently closed "curve Line[ s ]" should be understood and calculated as mere effects of rectilinear motions and rectilinear attraction. And as Newton was quick to realize, this also implied that "the planets neither move exactly in ellipse nor revolve twice in the same orbit, so that there are as many orbits to a planet as it has revolutions" (Herivel, 301: De Motu, Version III).