This book contains the contributed papers and reviews from IAU Colloquium Number 114 on White Dwarfs held at Dartmouth College in August 1988. All the current fields of research in this area are covered including the evolution of white dwarfs, links to progenitors, luminosity functions of white dwarfs, evolution of white dwarfs in binaries, spectroscopy and atmospheric abundances, diffusion, accretion and convective mixing, the mass-radius relation, gravitational redshifts, masses of white dwarfs, and magnetic white dwarfs. Special emphasis has been placed on the intrinsic properties of single white dwarfs. All the articles are by internationally known authorities and contain the most up-to-date information available at the time of writing.

Astronomy and Astrophysics Abstracts aims to present a comprehensive documen tation of the literature concerning all aspects of astronomy, astrophysics, and their border fields. It is devoted to the recording, summarizing, and indexing of the relevant publications throughout the world. Astronomy and Astrophysics Abstracts is prepared by a special department of the Astronomisches Rechen-Institut under the auspices of the International Astronomical Union. Volume 39 records literature published in 1985 and received before August 15, 1985. Some older documents which we received late and which are not surveyed in earlier volumes are included too. We acknowledge with thanks contributions of our colleagues all over the world. We also express our gratitude to all organiza tions, observatories, and publishers which provide us with complimentary copies of their publications. On account of the introduction of an object index the scope of index information will be considerably enlarged beginning with this volume. In connection with the subject index an additional source to satisfy the needs of retrieval is opened up. Starting with Volume 33, all the recording, correction, and data processing work was done by means of computers. The recording was done by our technical staff members Ms. Helga Ballmann, Ms. Mona El-Choura, Ms. Monika Kohl, Ms. Sylvia Matyssek. Ms. Karin Burkhardt, Ms. Susanne Schlotelburg, and Mr. Stefan Wagner supported our task by careful proofreading. It is a pleasure to thank them all for their encouragement. Heidelberg, September 1985 The Editors Contents Introduction . . . . . . . . . . . .

This volume is devoted to one of the fascinating things about stars: how they evolve as they age. This evolution is different for stars of different masses. How stars end their lives when their supply of energy is exhausted also depends on their masses. Interestingly, astronomers conjectured about the ultimate fate of the stars even before the details of their evolution became clear. Part I of this book gives an account of the remarkable predictions made during the 1920s and 1930s concerning the ultimate fate of stars. Since much of this development hinged on quantum physics that emerged during this time, a detailed introduction to the relevant physics is included in the book. Part II is a summary of the life history of stars. This discussion is divided into three parts: low-mass stars, like our Sun, intermediate-mass stars, and massive stars. Many of the concepts of contemporary astrophysics were built on the foundation erected by Subrahmanyan Chandrasekhar in the 1930s. This book, written during his birth centenary, includes a brief biographical sketch of the brilliant scientist, which readers will find fascinating.

Reading this book will get young students excited about the presently unfolding revolution in astronomy and the challenges that await them in the world of physics, engineering and technology. General readers will also find the book appealing for its highly accessible narrative of the physics of stars.

This book is a companion volume of What are the Stars? by the same author.

""I know of no other book on the evolution of stars of a similar scope and breadth that is so accessible for undergraduate students.""

E P J van den Heuvel
Professor of Astrophysics

Winner of the Spinoza and Descartes PrizesUniversity of Amsterdam, The Netherlands

"

Advances in the dynamics of stellar systems have been made recently by applying mathematical methods of ergodic theory and chaotic dynamics, by numerous computer simulations, and by observations with the most powerful telescopes. This has led to a considerable change of our view on stellar systems. These systems appear much more chaotic than was previously thought and subject to various instabilities leading to new paths of evolution than previously thought. The implications are fundamental for our views on the evolution of the galaxies and the universe. Such questions are addressed in this book, especially in the 8 review papers by leading experts on various aspects of the N-body problem, explaining at the graduate/postgraduate level the concepts, methods, techniques and results.

The volume consists of up-to-date reviews and a selection of contributed papers on subjects including the structure and physical properties of molecular clouds, their role in the star formation process, their dust and chemical properties, molecular cloud surveys of the Milky Way, cloud evolution, problems in cloud mass determinations (a panel discussion and review), the CO properties of external galaxies, nuclei of galaxies as revealed by molecular observations, and galactic spiral structure as reflected by molecular cloud distributions. The abstracts of poster papers on these topics presented at the conference are also included. This book is both a valuable reference and a compendium of current knowledge in this field. It should be of special interest to all students and researchers who work on the physics of star formation, the interstellar medium, molecular clouds and galactic structure.

Meant as a review for students of astrophysics and particle physics, this book contains a selection of survey articles and seminar reports on "high energy cosmology." Included are contributions on topics ranging from classical cosmology, large scale structure, and primordial nucleosynthesis to quantum cosmology, covering both the theoretical aspects and the most important observations.

This book begins with a very readable survey "The Sun Today" by J.-C. Pecker. It is followed by thorough reviews from leading experts covering theory and observations. The focus shifts from the solar core, studied via neutrino emissions and helioseismology, through the interface regions where it is believed the large-scale magnetic fields are generated, to the corona, where most of the high temperature phenomena characteristic of this region may be studied directly. As energetic particles play such a vigorous role in this part of the sun, a separate session was devoted to their transport and storage in the corona.

This ESO workshop, which took place in September 1995 on a topic that at a first glance could be considered rather specialized, attracted an unpre dictably large number of scientists. This certainly reflects the importance of this field, which has lost its seemingly esoteric character, in a wider astro physical context. To give as much room as possible in these proceedings to the targeted talks, no presentation of the Very Large Telescope Observatory has been included. All readers missing such a presentation are reminded that up-to date in-depth information about the VLT status is available electronically.1 Papers were given concerning observations in the entire electromagnetic spectrum from x-rays to mm-waves, i.e., exceeding 22 octaves in frequency. The VLT as any ground-based optical observatory can only address at best 7 octaves. Nevertheless the VLT, most likely the only ground-based observa tory specifically designed to access all these 7 octaves of the electromagnetic spectrum practically in parallel, will undoubtedly be a tool of extreme value to this field.

Written in a pedagogical way, the articles in this book address graduate students as well as researchers and are well suited for seminar work. Subjects at the forefront of nuclear research, bordering other areas of many-particle physics, such as electron scattering at different energy scales, new physics with radioactive beams, multifragmentation, relativistic nuclear physics, high spin nuclear problems, chaos, the role of the continuum in nuclear physics or recent calculations with the shell model are presented. It is felt that the topics treated in this book address the main future lines of development of nuclear physics.

The Solar and Heliospheric Observatory (SOHO) is a joint ESA/NASA mission to study the Sun, from its deep core to the outer corona, and the solar wind. SOHO was launched on 2 December 1995 and was inserted into a halo orbit around the L1 Lagrangian point on 14 February 1996. From this vantage point it is continuously monitoring the Sun, the heliosphere, and the solar wind particles that stream toward the Earth. Nominal operations of the SOHO mission started in April 1996 after commissioning of the spacecraft and the scientific payload. Detailed descriptions of the twelve instruments, which represent the most comprehensive set of solar and heliospheric instruments ever developed and placed on the same platform, can be found in "The SOHO" "Mission" ("Solar Physics," Vol. 162, Nos. 1-2, 1995).
This volume contains papers reporting the first scientific results from the SOHO mission as well as descriptions of the in-flight performance of some of the instruments, published in two parts of a "Solar Physics" special (Part I in "Solar Physics," Vol. 170, No. 1; Part II in "Solar Physics," Vol. 175, No. 2). Unique data from the three helioseismology instruments (GOLF, VIRGO, MDI/SOI) provide new insights into the structure and dynamics of the solar interior, from the deep core to the outermost layers of the convection zone. The remote sensing instruments (SUMER, CDS, EIT, LASCO, UVCS, SWAN) present exciting new data on a wide range of topics such as transition region dynamics, coronal plumes, coronal holes, streamers, and coronal mass ejections, giving us our first comprehensive view of the outer solar atmosphere and corona. These data are complemented by energetic particle measurements produced by the ERNE instrument on board SOHO.

Prominent progress in science is inevitably associated with controversies. Thus, young researchers, in particular, have to learn how to persevere during the period of controversy and struggle for acceptance. Unfortunately, the skills needed are not taught in textbooks or monographs, which mostly describe the consensus of contemporary experts.
This book, which is based on my own experiences as a scientist, describes the history of the progress made in auroral science and magnetospheric physics by providing examples of ideas, controversies, struggles, acceptance, and success in some instances.
Although no general methodology (if any exists) is mentioned, I hope that the reader will learn about the history of progress in auroral science and examples (right or wrong) of dealing with the controversies.

TheideaforthisbookoriginatedintheLaSillaobservatorywheretwoofthe editorsweredoingphase-resolvedspectroscopyofsomecataclysmicvariable starsusingtheNTT. Werealizedthatalthoughindirectimagingtechniques suchaseclipsemappingandDopplertomographyhadbeenaroundformore thanadecadeandhadprovidedsomeofthemostinterestingdiscoveries,no bookexistedwhichcoveredthesetechniques. Moreover,nocolloquiumhadever beenorganizedspeci?callyonthesetopics. Theimplementationoftomographic methodsinastrophysics,inordertoprobestructuresonangularscalesofmic- arcseconds,startedabout15yearsagowiththedevelopmentoftheeclipsem- pingmethod. Thismethodisabletoreconstructlightdistributionsineclipsing binariesbyexploitingtheregularobscurationofthelightsourcebyoneofthe binarycomponents. Asimilarapproachtoregulariseddata?ttingleadtoa- rietyofrelatedmethodsinordertoresolvelightdistributionsoftheaccretion ?owsinbinaries,thesurfacestructuresofstarsandtheinnerregionsofactive galaxies. Thescienti?coutputofthesemethodsisconsiderableandtheyare increasinglybecomingversatiletoolsforawidecommunityofresearchers. Aspecialisedworkshopseemedhighlydesirable,sowedecidedtoorganise the?rstinternationalworkshoponastrotomography. Theideaofthemeeting, whichtookplaceinBrusselsinearlyJuly2000,wastobringtogetherresearchers sharinganinterestinapplyingindirectimagingmethodsinastronomy,andto comparethemethodsusedindi?erent?elds. Duringthemeeting,alargeamount oftimewasdevotedtoextensivereviewsofthevariousreconstructiontechniques. Inconjunctionwiththereviews,shortcontributedtalkshighlightedrecent- sultsanddevelopments. Duetothesmallnumberofparticipants,60,therewas plentyofopportunityfordiscussionandinteraction. Moreover,wewantedthat theproceedingsofthismeetingcouldbeusedasahandbookonthesemethods. Thereviewerswerethereforeaskedtoprovideextensiveaccountsoftheir?eld. Theproceedingsthusconsistof13reviewsofabout25pageseachaswellas 15contributedtalksof6?8pages. Awiderangeoftopicsarediscussed,mostly onthepropertiesofaccretion?owsinsemi-detachedbinarysystemsconta- ingacompactstellarremnant. Othertopicsincludethesurfaceandmagnetic ?eldstructureofsinglestars,theshockwavesofMirastars,theaccretion?ows aroundblackholesinbinariesandactivegalacticnucleiandthestructureof Algolsystems. Thelargevarietyofsubjectscoveredisaclearillustrationofthe importancethatindirectimagingtechniqueshavegainedinastrophysics. Anew VI generationofopticaltelescopesandspectrographsiscomingon-linewhichwill pushthepossibilitiesofindirectimagingevenfurther. Inconjunctionwiththat, specialisedinstrumentsandprojectsonexistingtelescopeswilldeliverdatasets withhightimeandwavelengthresolutionstailoredforaccuratemapping- periments. Wehopethattheseproceedingswillprovideahelpfuloverviewfor anyresearcherinterestedinsuchtechniques. Withthesamespiritofproducing morethanjustproceedings,wealsoincludealistofsomeusefulresourceson theInternet. Wealsohopethatthewebpageoftheworkshopwillbekeptalive andbecomeausefulreferenceonastrotomography. Wewouldliketothankalltheparticipantsformakingthisworkshopas- cess,andinparticularallthecontributingreviewauthorsforhavinggenerously agreedtocometothemeetingattheirownexpense,andfortheire?ortsin providingabalancedsetofreviewpapers. Manythankstoallthemembersof thelocalorganisingcommitteeforthehardworkbefore,duringandafterthe workshop. TheBrusselsPlanetariumisthankedforprovidinguswithameeting venueandexcellentsupport. WealsowishtothanktheDirectoroftheRoyal ObservatoryofBelgium,Prof. PaulPaquet,forhise?orts. RobHynesprovided uswithasuperb'scienti?cimpression'ofaninteractingbinarythatfeaturedon theworkshopposterandvariousotherlocations. Finally,wearegratefulfo- nancialsupportfromprojectG. 0265. 97oftheResearchProgrammeoftheFund forScienti?cResearch-Flanders(F. W. O. -Vlaanderen). Brussels,Southampton, HenriBo?n, November2000 DannySteeghs, JanCuypers Workshopwebpage:http://www. astro. oma. be/DopplerWorkshop/ Contents DopplerTomography T. R. Marsh...1 MappingthePeculiarBinaryGPCom L. Morales-Rueda,T. R. Marsh,R. C. North...27 H?-EmissionDopplerTomography ofLong-PeriodCataclysmicVariableStars R. C. North,T. R. Marsh,C. K. J. Moran,U. Kolb,R. C. Smith,R. Stehle. . 33 DopplerTomographyoftheDwarfNovaIYUMa duringQuiescence D. J. Rolfe,T. M. C. Abbott,C. A. Haswell...39 SpiralWavesinAccretionDiscs-Observations D. Steeghs...45 SpiralWavesinAccretionDiscs-Vlaanderen). Brussels,Southampton, HenriBo?n, November2000 DannySteeghs, JanCuypers Workshopwebpage:http://www. astro. oma. be/DopplerWorkshop/ Contents DopplerTomography T. R. Marsh...1 MappingthePeculiarBinaryGPCom L. Morales-Rueda,T. R. Marsh,R. C. North...27 H?-EmissionDopplerTomography ofLong-PeriodCataclysmicVariableStars R. C. North,T. R. Marsh,C. K. J. Moran,U. Kolb,R. C. Smith,R. Stehle. . 33 DopplerTomographyoftheDwarfNovaIYUMa duringQuiescence D. J. Rolfe,T. M. C. Abbott,C. A. Haswell...39 SpiralWavesinAccretionDiscs-Observations D. Steeghs...45 SpiralWavesinAccretionDiscs-TheideaforthisbookoriginatedintheLaSillaobservatorywheretwoofthe editorsweredoingphase-resolvedspectroscopyofsomecataclysmicvariable starsusingtheNTT. Werealizedthatalthoughindirectimagingtechniques suchaseclipsemappingandDopplertomographyhadbeenaroundformore thanadecadeandhadprovidedsomeofthemostinterestingdiscoveries,no bookexistedwhichcoveredthesetechniques. Moreover,nocolloquiumhadever beenorganizedspeci?callyonthesetopics. Theimplementationoftomographic methodsinastrophysics,inordertoprobestructuresonangularscalesofmic- arcseconds,startedabout15yearsagowiththedevelopmentoftheeclipsem- pingmethod. Thismethodisabletoreconstructlightdistributionsineclipsing binariesbyexploitingtheregularobscurationofthelightsourcebyoneofthe binarycomponents. Asimilarapproachtoregulariseddata?ttingleadtoa- rietyofrelatedmethodsinordertoresolvelightdistributionsoftheaccretion ?owsinbinaries,thesurfacestructuresofstarsandtheinnerregionsofactive galaxies. Thescienti?coutputofthesemethodsisconsiderableandtheyare increasinglybecomingversatiletoolsforawidecommunityofresearchers. Aspecialisedworkshopseemedhighlydesirable,sowedecidedtoorganise the?rstinternationalworkshoponastrotomography. Theideaofthemeeting, whichtookplaceinBrusselsinearlyJuly2000,wastobringtogetherresearchers sharinganinterestinapplyingindirectimagingmethodsinastronomy,andto comparethemethodsusedindi?erent?elds. Duringthemeeting,alargeamount oftimewasdevotedtoextensivereviewsofthevariousreconstructiontechniques. Inconjunctionwiththereviews,shortcontributedtalkshighlightedrecent- sultsanddevelopments. Duetothesmallnumberofparticipants,60,therewas plentyofopportunityfordiscussionandinteraction. Moreover,wewantedthat theproceedingsofthismeetingcouldbeusedasahandbookonthesemethods. Thereviewerswerethereforeaskedtoprovideextensiveaccountsoftheir?eld. Theproceedingsthusconsistof13reviewsofabout25pageseachaswellas 15contributedtalksof6?8pages. Awiderangeoftopicsarediscussed,mostly onthepropertiesofaccretion?owsinsemi-detachedbinarysystemsconta- ingacompactstellarremnant. Othertopicsincludethesurfaceandmagnetic ?eldstructureofsinglestars,theshockwavesofMirastars,theaccretion?ows aroundblackholesinbinariesandactivegalacticnucleiandthestructureof Algolsystems. Thelargevarietyofsubjectscoveredisaclearillustrationofthe importancethatindirectimagingtechniqueshavegainedinastrophysics. Anew VI generationofopticaltelescopesandspectrographsiscomingon-linewhichwill pushthepossibilitiesofindirectimagingevenfurther. Inconjunctionwiththat, specialisedinstrumentsandprojectsonexistingtelescopeswilldeliverdatasets withhightimeandwavelengthresolutionstailoredforaccuratemapping- periments. Wehopethattheseproceedingswillprovideahelpfuloverviewfor anyresearcherinterestedinsuchtechniques. Withthesamespiritofproducing morethanjustproceedings,wealsoincludealistofsomeusefulresourceson theInternet. Wealsohopethatthewebpageoftheworkshopwillbekeptalive andbecomeausefulreferenceonastrotomography. Wewouldliketothankalltheparticipantsformakingthisworkshopas- cess,andinparticularallthecontributingreviewauthorsforhavinggenerously agreedtocometothemeetingattheirownexpense,andfortheire?ortsin providingabalancedsetofreviewpapers. Manythankstoallthemembersof thelocalorganisingcommitteeforthehardworkbefore,duringandafterthe workshop. TheBrusselsPlanetariumisthankedforprovidinguswithameeting venueandexcellentsupport. WealsowishtothanktheDirectoroftheRoyal ObservatoryofBelgium,Prof. PaulPaquet,forhise?orts. RobHynesprovided uswithasuperb'scienti?cimpression'ofaninteractingbinarythatfeaturedon theworkshopposterandvariousotherlocations. Finally,wearegratefulfo- nancialsupportfromprojectG. 0265. 97oftheResearchProgrammeoftheFund forScienti?cResearch-Flanders(F. W. O. -Vlaanderen). Brussels,Southampton, HenriBo?n, November2000 DannySteeghs, JanCuypers Workshopwebpage:http://www. astro. oma. be/DopplerWorkshop/ Contents DopplerTomography T. R. Marsh...1 MappingthePeculiarBinaryGPCom L. Morales-Rueda,T. R. Marsh,R. C. North...27 H?-EmissionDopplerTomography ofLong-PeriodCataclysmicVariableStars R. C. North,T. R. Marsh,C. K. J. Moran,U. Kolb,R. C. Smith,R. Stehle. . 33 DopplerTomographyoftheDwarfNovaIYUMa duringQuiescence D. J. Rolfe,T. M. C. Abbott,C. A. Haswell...39 SpiralWavesinAccretionDiscs-Observations D. Steeghs...45 SpiralWavesinAccretionDiscs-Theory H. M. J. Bo?n...69 SpiralShocksinanInviscidSimulationofAccretionFlow inaCloseBinarySystem M. Makita,H. Fujiwara,T. Matsuda,H. M. J. Bo?n...88 ImagingtheSecondaryStarsinCataclysmicVariables V. S. Dhillon,C. A. Watson...9 4 StatisticsofIsolatedEmissionSourcesinCataclysmicVariables C. Tappert,R. Hanuschik...119 TomographyofPolars A. Schwope...127 TomographyofMagneticAccretionFlows G. Wynn...155 VIII Contents TheGeometricalCon?gurationofPolars andPossibleReconstructionArtefacts ofEclipseMappingMethods J. Kube...175 SpotMappinginCoolStars A. CollierCameron...183 ImagingtheMagneticTopologiesofCoolActiveStars J. -F. Donati...207 Di?erentialRotationofCloseBinaryStars: ApplicationtoHR1099 P. Petit, J. -F. Donati, G. A. Wade, J. D. Landstreet, J. M. Oliveira, S. L. S. Shorlin,T. A. A. Sigut,A. C. Cameron...232 MagneticDopplerImagingofChemicallyPeculiarStars N. Piskunov,O. Kochukhov...238 StokesImagingoftheAccretionRegion inMagneticCataclysmicVariables S. Potter,E. Romero-Colmenero,D. A. H. Buckley,M. Cropper, P. Hakala...244 DopplerImagesoftheMDwarfRE1816+541 J. R. Barnes,A. CollierCameron...252 TheMethodofSpectraDisentangling andItsLinkstoDopplerTomography P. Hadrava...

The articles in this volume are a document of the Galileo mission to Jupiter. The Mission Overview is the first article; the second is a description of the design of the very complex spacecraft trajectory in relation to the scientific objects. Subsequent articles describe the various investigations planned by the scientific groups. These are divided in three groups: the Probe, the Magnetospheric Experiments, and the Remote Sensing and Radio Investigations.

During the first decades after Einstein had developed his Theory of General Relativity, the main effort was to understand the theory and verify it experimentically. Meanwhile Genral Relativity is one of the experimentally best confirmed theories and has become a powerful tool for the investigation of cosmic processes where strong gravitational fields are involved.
This book contains 16 contributions from well-known experts giving a broad overview for non-specialists who want to learn how to purely academic issues like gravitational wave detectors are now put into reality.

IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) is the first NASA MIDEX mission and the first mission dedicated to imaging the Earth's magnetosphere. This volume offers detailed descriptions of the IMAGE instrumentation and of the image inversion techniques used to interpret the data. Also included are chapters on the IMAGE science objectives, the spacecraft design and capabilities, science and mission operations, and the processing and distribution of IMAGE's nonproprietary data products.

This textbook is intended as an introduction to the physics of solar and stellar coronae, emphasizing kinetic plasma processes. It is addressed to observational astronomers, graduate students, and advanced undergraduates without a ba- ground in plasma physics. Coronal physics is today a vast field with many different aims and goals. So- ing out the really important aspects of an observed phenomenon and using the physics best suited for the case is a formidable problem. There are already several excellent books, oriented toward the interests of astrophysicists, that deal with the magnetohydrodynamics of stellar atmospheres, radiation transport, and radiation theory. In kinetic processes, the different particle velocities play an important role. This is the case when particle collisions can be neglected, for example in very brief phenomena - such as one period of a high-frequency wave - or in effects produced by energetic particles with very long collision times. Some of the most persistent problems of solar physics, like coronal heating, shock waves, flare energy release, and particle acceleration, are likely to be at least partially related to such p- cesses. Study of the Sun is not regarded here as an end in itself, but as the source of information for more general stellar applications. Our understanding of stellar processes relies heavily, in turn, on our understanding of solar processes. Thus an introduction to what is happening in hot, dilute coronae necessarily starts with the plasma physics of our nearest star.

Transport Processes in Space Physics and Astrophysics is aimed at graduate level students to provide the necessary mathematical and physics background to understand the transport of gases, charged particle gases, energetic charged particles, turbulence, and radiation in an astrophysical and space physics context. Subjects emphasized in the work include collisional and collisionless processes in gases (neutral or plasma), analogous processes in turbulence fields and radiation fields, and allows for a simplified treatment of the statistical description of the system. A systematic study that addresses the common tools at a graduate level allows students to progress to a point where they can begin their research in a variety of fields within space physics and astrophysics. This book is for graduate students who expect to complete their research in an area of plasma space physics or plasma astrophysics. By providing a broad synthesis in several areas of transport theory and modeling, the work also benefits researchers in related fields by providing an overview that currently does not exist.
For numerous interesting and challenging space physics and astrophysics problems, there is a need to describe the long-term behavior of systems governed by macroscopic laws and microscopic randomness. A random event has an outcome that is uncertain and unpredictable, yet the collective behavior of a system can be governed by well defined mathematical and physical principles. Examples of physical problems include the behavior of gases in the presence of microscopic inter-particle collisions, the evolution of a gas of charged protons and electrons (a plasma), the collective propagation of solar energetic particles or cosmic rays in a magnetically turbulent medium, the collective behavior of dust in an accretion disk subject to coagulation and destruction, the evolution of low-frequency magnetic field turbulence in the inhomogeneous solar wind, or the transport of photos in a partially ionized interstellar medium. This book provides graduate students with a unified introduction to the physics of collective phenomena or transport processes for gases (charged and uncharged), fields, and photons in a space physics or astrophysics context."

In this "SpringerBrief" the author considers the underlying problems and questions that are common to numerical models of turbulence in different astrophysical systems. Turbulence has emerged as an important research topic in several areas of astrophysics. Understanding and modeling turbulence is particularly important for the dynamics of the interstellar medium, but also for the intergalactic medium, as well as in stars. The advancement of methods for numerical simulations of astrophysical turbulence, however, is still challenging because of gravity, strong compressibility, magnetic fields, and other effects. The book begins with a review of general aspects of numerical simulations of turbulence. In the main part the author presents findings from his numerical studies on astrophysical turbulence and discusses the astrophysical implications. He also explains in detail the numerical schemes utilized. Readers will find that this book offers a compact yet comprehensive introduction.

This modern presentation guides readers through the theory and practice of satellite orbit prediction and determination. Starting from the basic principles of orbital mechanics, it covers elaborate force models as well as precise methods of satellite tracking. The accompanying CD-ROM includes source code in C++ and relevant data files for applications. The result is a powerful and unique spaceflight dynamics library, which allows users to easily create software extensions. An extensive collection of frequently updated Internet resources is provided through WWW hyperlinks.

The seeds of this conference were sown with the publication by Press, in 1965, of a paper in which he suggested that the displacement field due to a major earthquake may extend over much greater distances than had been thought possible before. Later on, Mansinha and Smylie pointed out that if Press was correct then, since the redistri bution of significant quantities of mass was involved, the inertia tensor of the earth would be altered and thus cause the earth to wobble; this revived the idea that earth quakes might be the long sought source for maintaining the Chandler Wobble. They argued that since earthquakes are sudden events it should be worthwhile trying to determine if there was any correlation between sudden changes in the Chandler term of the pole path and major earthquakes. Furthermore, since displacements occur both before and after an earthquake it might be possible to obtain a few days warning of a major earthquake by making instantaneous observations of the pole path. Analysis of the data indicated some correlation but, as often happens in science in general and in geophysics in particular, the results were not conclusive because of imperfect theory and the need for more accurate determinations of the pole position. It soon became clear that a meeting between geophysicists and astronomers involved in this type of work would be of mutual benefit."

The study of the fine structure of solar radio emissions is key to understanding plasma processes in the solar corona. It remains a reliable means for both diagnosing the corona and verifying the results of laboratory plasma experiments on wave-wave and wave-particle interactions. This monograph provides a comprehensive review of the fine structure of solar radio bursts. Based on the diversity of experimental data resulting from the progress made in observational techniques, the validity of various theoretical models is reexamined. The book serves as an up-to-date reference work for all researchers in this field.

This volume is published in honor of Friedrich Hund's 100th birthday. It is a modern review on matter at high densities and pressures in astrophysics from Hund's early contribution to present-day ideas. The relation between the equation of state and the structure of compact cosmic objects is discussed, and two main contributions deal with the equation of state of baryonic matter at nuclear densities and with the numerical solution of the general relativistic field equations for non-rotating and rapidly rotating neutron stars. In a final chapter the present state of asteroseismology is presented as a tool to explore the interior of cosmic objects by analyzing the observed free oscillations of the Earth, the Sun, and white dwarf stars.

This is an exhaustive review of our theoretical and observational knowledge of gravitational lensing 10 years after the discovery of the first lensed quasar, Q0957+561. Gravitational optics, optical, infrared, and radio observations of quasar-lens candidates, microlensing, arcs in clusters of galaxies, and radio rings are presented. In particular, the continuing survey of quasar-lens candidates, the new measurement of the time delay in 0957+561, the suspended microlensing effect through the galaxy 2237+030, as well as the discovery of new arcs and the measurement of new redshifts for two of them are presented. Numerous papers on the modelling of arcs and rings show how it should be possible to probe dark matter with these unexpected gravitational telescopes. Finally, tables summarize all the lens candidates we know today.

Astronomy and Astrophysics Abstracts, which has appeared in semi-annual volumes since 1969, is de voted to the recording, summarizing and indexing of astronomical publications throughout the world. It is prepared under the auspices of the International Astronomical Union (according to a resolution adopted at the 14th General Assembly in 1970). Astronomy and Astrophysics Abstracts aims to present a comprehensive documentation of literature in all fields of astronomy and astrophysics. Every effort will be made to ensure that the average time interval between the date of receipt of the original literature and publication of the abstracts will not exceed eight months. This time interval is near to that achieved by monthly abstracting journals, com pared to which our system of accumulating abstracts for about six months offers the advantage of greater convenience for the user. Volume 18 contains literature published in 1976 and received before March 1, 1977; some older liter ature which was received late and which is not recorded in earlier volumes is also included.

Theideatocelebrate50yearsoftheSalpeterIMFoccurredduringtherecent IAU General Assembly in Sydney, Australia. Indeed, it was from Australia that in July 1954 Ed Salpeter submitted his famous paper "The Luminosity Function and Stellar Evolution" with the rst derivation of the empirical stellar IMF. This contribution was to become one of the most famous astrophysics papers of the last 50 years. Here, Ed Salpeter introduced the terms "original mass function" and "original luminosity function", and estimated the pro- bility for the creation of stars of given mass at a particular time, now known as the "Salpeter Initial Mass Function", or IMF. The paper was written at the Australian National University in Canberra on leave of absence from Cornell University (USA) and was published in 1955 as 7 page note in the Astroph- ical Journal Vol. 121, page 161. To celabrate the 50th anniversary of the IMF, along with Ed Salpeter's 80th birthday, we have organized a special meeting that brought together scientists involved in the empirical determination of this fundamental quantity in a va- ety of astrophysical contexts and other scientists fascinated by the deep imp- cations of the IMF on star formation theories, on the physical conditions of the gas before and after star formation, and on galactic evolution and cosmology. The meeting took place in one of the most beautiful spots of the Tuscan countryside, far from the noise and haste of everyday life.