bluuebunny/crossref_metadata_2025 huggingface dataset:
The Biblical Flood as a Geological Agent: A Review of Theories
Authors: Young Davis A.
Published: June 2019

Mainstream scientists, including Woodward, Buckland, Prestwich, Suess, and Ryan and Pitman, have proposed a variety of theories to explain the biblical deluge. The extent of the flood in these theories has decreased as empirical knowledge of global geology has increased. In contrast, contemporary flood geology attempts to explain most of the geologic record in terms of a single, year-long, global catastrophe. Flood geology exists in the context of an alternate scientific universe with its own institutions, organizations, journals, and meetings. The views of Leonard Brand, Steven Austin, and Walt Brown, representative of flood geology, are discussed.
Faith of a Paleontologist
Authors: Dodson Peter
Published: June 2019

Evolution is the great synthesizing principle of biology and cosmology that our students deserve to know in order to understand their world most fully. Yet evolution has social Darwinism as its dark side. An evolutionism or a scientism that teaches in the name of science that there is no God, there is no soul, there is no ultimate purpose in life, and there is no such thing as free will is not the friend of society. Creationists reject evolution not in ignorance of modern science but because of the anxieties it brings. While 90% of Americans profess to believe in God, less than half the population believes in some form of evolution. Science discounts human experience, while religion is about human experience. When forced to choose between a religion that enriches human experience and an evolutionary science that ignores human experience and minimizes humans as a species, people will unhesitatingly choose the religion that gives meaning to their daily struggles. That choice is not a necessary one, but so long as the most visible public spokespersons for evolution pursue their metaphysical agenda, people will continue to choose religion.
Common Mistakes in Comparing Biblical and Scientific Maps of Origins
Authors: Hyers Conrad
Published: June 2019

The history of controversy over evolution and the bible is a history of confusion between biblical and scientific approaches to origins. Taking some cues from John Calvin who, in the 16th century, addressed the emerging controversies over cosmology, the paper examines a variety of differences between biblical and scientific types of literature as they deal with cosmogony. Biblical uses of phenomenal observation, analogical reasoning, numerology, and theological critique are distinguished from the approaches to origins used in modern scientific and historical investigations. Their respective models of origins are not in conflict unless they are mistakenly seen as mapping in the same way and for the same purposes.
Predators and Predation in Paleozoic Marine Environments
Authors: Brett Carlton E. , Walker Sally E.
Published: June 2019

The Paleozoic body fossil record of potential benthic predators includes nautiloid and ammonoid cephalopods, phyllocarids, decapods, and several lineages of gnathostomes. The latter group, in particular, radiated rapidly during the Devonian. In the pelagic realm, predator-prey interactions involving cephalopods and some nektonic arthropods probably appeared in the Ordovician. Again, evidence indicates intensification of pelagic predation, much of it by arthrodires and sharks on other fishes, during the Devonian radiation of gnathostomes.

Trace fossils provide direct evidence of predatory attack from the Ediacarian and Early Cambrian onward, but with a substantial increase in the Siluro-Devonian. Brachiopod and molluscan shells and trilobite exoskeletons show evidence of healed bite marks and peeling from the Cambrian onward, but with an increased frequency in the Devonian. Predatory drill holes with stereotypical position and prey-species preference are found in brachiopods (Cambrian onward) and mollusks (Ordovician onward); boreholes also show increased frequency in the middle Paleozoic. Certain of these boreholes are tentatively attributable to platyceratid gastropods.

Hard-shelled benthic organisms with thicker, more spinose skeletons may have had a selective advantage as durophagous predators increased. Brachiopods, gastropods, trilobites, and crinoids show an abrupt increase in spinosity beginning in the Siluro-Devonian. But spinosity decreases after the early Carboniferous. Late Paleozoic benthos may have taken refuge in smaller size and resistant, thick-walled skeletons, as well as endobenthic and cementing modes of life. Conversely, in the pelagic realm, external armor was reduced, while more efficient, fast-swimming modes of life (e.g., in sharks) increased in the post-Devonian.
Scientific Progress: Beyond Foundationalism and Coherentism
Authors: Chang Hasok
Published: June 2019

Scientific progress remains one of the most significant issues in the philosophy of science today. This is not only because of the intrinsic importance of the topic, but also because of its immense difficulty. In what sense exactly does science makes progress, and how is it that scientists are apparently able to achieve it better than people in other realms of human intellectual endeavour? Neither philosophers nor scientists themselves have been able to answer these questions to general satisfaction.
Counter Thought Experiments
Authors: Brown James Robert
Published: June 2019

Let's begin with an old example. In De Rerum Naturua, Lucretius presented a thought experiment to show that space is infinite. We imagine ourselves near the alleged edge of space; we throw a spear; we see it either sail through the ‘edge’ or we see it bounce back. In the former case the ‘edge’ isn't the edge, after all. In the latter case, there must be something beyond the ‘edge’ that repelled the spear. Either way, the ‘edge’ isn't really an edge of space, after all. So space is infinite.
A conversation with Alain Schnapp
Authors: Hamilakis Yannis , Rojas Felipe
Published: June 2019

On 13 November 2017, Yannis Hamilakis, Felipe Rojas, and several other archaeologists at Brown University engaged in a conversation with Alain Schnapp about his life and career. Hamilakis and Rojas were interested in learning about how Schnapp’s early academic and political interests intersected with the history of Classics and classical archaeology in France, Europe and elsewhere in the world, and also about the origins and current aims of Schnapp’s work on the history of archaeology and antiquarianism and the cross-cultural history of ruins. Schnapp and his interlocutors began by discussing Schnapp’s formative years and the intersections between archaeology and politics in mid-20th-century France. Their conversation turns to the role of individual scholars, specifically classicists and archaeologists, in the momentous social events in Paris in 1968. The final part of the dialogue concerns Schnapp’s contributions to the history of archaeology and the possibilities of engaging in the comparison of antiquarian traditions.
Changing the milk supply to increase cheese yield: The Kaikoura experience
Authors: Boland M. , Hill J. , O’Connor P.
Published: June 2019

This paper describes the steps that were taken to increase the productivity of a commercial cheese company by genetically altering the milk composition. These steps included validation of the effect of b–lactoglobulin polymorphism on casein production and cheese yield under typical New Zealand pastoral farming conditions, manufacture and ripening of cheese from single variant milks, selection of a suitable company to trial breeding for a single variant, development of a suitable payment scheme to reflect the additional value of the higher casein milk, development of a testing regime to support the payment system and getting buy–in from the company. These steps have all been taken, and the company has pursued the recommended breeding strategy for 3 years, purchased instrumentation and elected to move to the new testing and payment scheme for the current dairy season.
Dumb animals and smart machines: the implications of modern milking systems for integrated management of dairy cows
Authors: Mottram T. T. , Masson L.
Published: June 2019

The dairy industry has continued to innovate to meet the needs of the consumers' specification of milk at a low price, of good hygienic quality and with rising expectations of animal welfare. The introduction of robotic milking offers the opportunity for the cost effective deployment of novel sensors for a variety of milk analytes. Traditional methods of monitoring health changes in animals are based entirely on the human senses. However, in modern milking systems humans rarely have enough time to see the cows to observe for signs of ill health, the extreme case is that of robotic milking. Novel sensors will allow closed loop control systems where the early detection of deviations from optimal performance will enable the farm manager to make management decisions before damage to potential milk yields is irreversible. Where a biological model already exists, for example, in the prediction of ovulation with milk progesterone analysis, rapid progress is being made towards an automated prediction system. Integrated management systems for dairy cows will not only have the traditional goals of efficient milk production but can also be tuned to reduce polluting outputs of ammonia, phosphorus and methane. The main metabolic markers in milk to be monitored are urea, fat, ketones and protein. The detection of mastitis can be achieved by the development of sensor systems to detect enzyme markers of inflammatory response such as Nagase. Multi-disciplinary research is needed to develop integrated management systems drawing all the different elements of dairy cow management into a single system. The major cause of death in dairy cows is dystocia and monitoring systems are needed to ensure that parturition is better managed.
Within milking variation of urea, acetone, fat and protein and the determination of sampling time for an on-line system
Authors: Masson L.L. , Mottram T.T. , Garnsworthy P.C.
Published: June 2019

Sampling for analysis of milk constituents (fat and protein) is a routine procedure on commercial dairy farms. It is assumed that for this procedure a representative sample of whole milk is taken, either as a fractionated sample from the milk meter or as a thoroughly mixed milk sample taken after the milk has been agitated with air in the recording jar. The use of on-line sensors for milk analysis will provide real-time data on which nutritional management decisions can be made according to milk composition. However, there is no recommendation as to the optimum sampling time in an on-line system to obtain a representative sample during the milking process. Ideally sampling should be carried out as early as possible for the analysis to be completed before the milking system is needed for the next cow. It is important to establish within milking variation of milk constituents for an on-line sensing system, especially since fat increases significantly throughout milking. The aims of this study were to determine the within milking variation of urea, acetone, fat and protein and to specify the most appropriate time of sampling within milking to obtain representative concentrations of these constituents and analytes.
The Livestock Revolution - a view on implications for Africa
Authors: Mwangi D.M. , Omore A.
Published: June 2019

A rapid growth in per capita consumption of livestock products is occurring in developing countries (Delgado et al., 1999; FOASTAT 1983-2002). In the last two decades and until 2020, the increase in the consumption of meat and milk has been estimated to be much higher in developing countries compared to developed countries (Delgado et al. 1999). This increase in consumption and demand is fuelling an increase in production.
Meeting the increased demand for animal products in Asia: opportunities and challenges for research
Authors: Devendra C.
Published: June 2019

Improved animal production and productivity enhancement in Asia are justified in direct response to the need for more animal proteins. This need is associated with rising incomes, which encourage people to diversify their diets to include a variety of meats, eggs and dairy products, including the substitution of calories in livestock for low-priced starch calories. The projected total meat and milk human consumption levels in 2020 are far in excess of anticipated supplies (Degaldo et al., 1999). The rapid growth in the consumption of foods of animal origin is especially spectacular in East and South East Asia where the demand growth has placed unprecedented pressure on the management of the natural resources (crops, animals, land and water).
GM technology: a tool to benefit livestock production
Authors: Phipps R.H. , Cockburn A.
Published: June 2019

The limitations to livestock production are numerous and varied but are applicable to a greater or lesser extent in both developed and developing countries. Crop factors that limit livestock production include inadequate quality (e.g. crop residues such as maize stover) and quantity of feed resources with an inconsistent supply due to extremes of climate (e.g. low rainfall and high temperatures), the presence of anti-nutritional factors and toxins (e.g. trypsin inhibitors, glucosinolates, gossypol, mycotoxins), and deficiencies of specific nutrients (e.g. amino acids and minerals).
A comparative analysis of milk sectors - Nairobi, Kathmandu, Santa Cruz: Opportunities for pro-poor policies
Authors: Anderson S. , Rushton J. , Tulachan P. M. , Staal S. , Herrero M.
Published: June 2019

The paper presents the main findings of a set of comparative milk sector surveys carried out in Kathmandu (Nepal), Nairobi (Kenya) and Santa Cruz (Bolivia). The surveys assessed changes in demand, supply and marketing of milk and milk products over a ten to fifteen year period to 2001. The paper considers demand for milk and milk products, changes in milk supply and trading pathways, the policy frameworks, changes in demand and market share, and growth in the sector and poverty reduction. The policy implications for propoor development of the milk sector are discussed.
Venus
Authors: Sagdeev R.
Published: June 2019

I feel very honoured at having been asked by the IAU Executive to present Prof. Sagdeev’s invited discourse on Venus in his absence. As has already been mentioned Prof. Sagdeev was summoned to the talks between the USSR and the USA in Geneva as an expert in Space Research. He went there with several very important proposals for future cooperation in scientific exploration of outer space and we all hope that the results of his mission will be beneficial for the development of space astronomy and therefore for the whole astronomical community represented by the International Astronomical Union. I am sure that all present in this room realize that it is not an easy task to present someone else’s lecture especially at such short notice and in a foreign language. Besides, it is my opinion that a talk on Venus – the brightest celestial body in the sky except the moon and the Sun – Venus which always has been the symbol of beauty, love and femininity, that such a talk should surely be given by a man.
Status Report of the Work on the FK5
Authors: Schwan H.
Published: June 2019

A survey is given on the tasks to be performed in the process of improving a fundamental system. Completed tasks are the derivation of corrections to the values for general precession and the determination of the FK4 equinox and equator. The selection of new fundamental stars and the improvement of the systematic and individual accuracy of the FK4 is in progress. A description of the observational material and of new methods of analysis is given. Preliminary results are reported.
J2000.0
Authors: Smith Clayton
Published: June 2019

It was recommended in a resolution of the International Astronomical Union that as of Jan. 1, 1984, a new astronomical reference frame would be adopted (IAU 1976). This reference frame has been designated as the FK5 reference frame of J2000.0. The problem of the interim realization of this reference frame pending completion of work on the compilation of the FK5 catalog at the Astronomisches Rechen-institut has been addressed by a number of authors, see, e.g., Kaplan(1981), Standish(1983), Aoki et al.(1983), and Lederle and Schwan(1984). Their discussions are primarily concerned with the steps which must be taken to transform FK4 catalog positions and proper motions referred to the equator, equinox and epoch of B1950.0 to J2000.0. The primary emphasis of the following discussion is on the transformation of catalogs other than the FK4 to the J2000.0 equinox. There are a few remarks concerning the FK4 catalog.
Classical Absolute/Differential Programs
Authors: Morrison L V
Published: June 2019

In astronomy we try to determine a non-rotating frame from analyses of the observed motions of three mechanical systems – the solar system, the galaxy and the extragalactic nebulae. The rotation of the extragalactic frame is of the order 10-10 arcsec per century, so, for all practical purposes, this frame may be regarded as having no rotation. The other two frames are model-dependent and, as such, cannot be regarded ab initio as constituting non-rotation frames of reference. These reference frames are linked by various techniques, as shown in the diagram below.
The Background to the Merit/Cotes Recommendations on the Terrestrial and Celestial Reference Systems
Authors: Wilkins G A
Published: June 2019

The MERIT programme of international collaboration to monitor earth-rotation and to intercompare the techniques of observation and analysis has fostered the development of the use of space techniques. Earth-rotation parameters are now determined regularly with a precision that is better than 1 milliarcsecond () and the relative positions of the observing stations are determined to better than 1 decimetre (0.1 m). It is therefore necessary that the terrestrial and celestial reference frames be defined more precisely. The MERIT and COTES Working Groups have proposed that new conventional terrestrial and celestial reference systems be established and that the maintenance of these systems be the responsibility of a new International Earth Rotation Service. The new reference frames are to be based on the adoption of positions and motions of designated stations and extragalactic radio sources. Appropriate models and parameters will be associated with these frames to form reference systems so that observations can be used to determine the rotation of the terrestrial frame with respect to the celestial frame.
Proper Motions Referred to Faint Galaxies
Authors: van Altena W. F. , Girard T. , López C. E. , Klemola A. R. , Jones B. F. , Hanson R. B.
Published: June 2019

The Lick Northern Proper Motion (NPM) and the Yale-San Juan Southern Proper Motion (SPM) programs have been described on several occasions (Wright 1950; Deutsch and Klemola 1974; Vasilevskis 1973; and Wesselink 1974). The two programs represent an attempt to measure the coordinates and proper motions, with respect to the extragalactic reference frames, for large numbers of stars representing most of the astrophysically-recognized classes. The photographic plate material forming the basis of the NPM program derives from the first (1947-1954) and second (1970-present) epoch phases for 1246 fields with the Lick 51 cm Carnegie double-astrograph for centers at -20° and northward (Shane and Wirtanen 1967). A southern supplement of 144 additional fields takes the program to -30°. The SPM consists of 632 fields with centers at -20° and southward. The first epoch plates were taken between 1965 and 1974 and a partial extension of 72 fields to more northerly declinations is essentially complete. One short and one long exposure permit the measurement of positions and approximate photometry for selected stars and reference galaxies over the blue magnitude range from about 8 to 17-18.
Reference Frame Studies at JPL/Caltech
Authors: Dickey J. O. , Esposito P. B. , Lestrade J.-F. , Linfield R. P. , Melbourne W. G. , Newhall X X , Niell A. E. , Preston R. A. , Standish E. M. , Williams J. G. , Muhleman D. O. , Berge G. L. , Rudy D. J.
Published: June 2019

In recent years, a revolution in astronomical position measurements has been taking place with the advent of modern space techniques. These new techniques, which supplement the traditional astrometric measurements, include laser ranging to the moon and artificial satellites, very-long-baseline interferometry (VLBI) of galactic and extra-galactic radio sources and spacecraft, radio tracking of satellites, and radar-ranging and spacecraft tracking during planetary encounters. Impressive accuracies have been achieved and further improvements are forthcoming. Each technique can be expected to establish its own reference frame which is derived from observations of a particular class of objects. The celestial and terrestrial coordinate systems are related through adopted constants and definitions. Contemporary astronomy has led to the development of three principal celestial coordinate systems: the optical frame (FK4/FK5) based on positions of galactic stars; the planetary/lunar ephemeris frame based on the major celestial bodies of the solar system; and the radio frame constructed from observations of extragalactic radio sources (quasars). Each frame is rotated with respect to others; furthermore, the optical frame offset is time variable. It is important that all frames be interconnected and unified. The optical frame is being connected to the radio frame by VLBI observations of radio emitting stars. The radio frame is being tied to the ephemeris frame in several ways – one is via differential VLBI measurements between quasars and planet-orbiting spacecraft.
Relativistic Reference Frames in Astrometry
Authors: Murray C A
Published: June 2019

Astrometry can be defined as the measurement of space-time coordinates of photon events. For example, in principle, in classical optical astrometry, we measure the components of velocity, and hence the direction, of an incoming photon with respect to an instrumental coordinate system, and the clock time, at the instant of detection. The observer’s coordinate system at any instant can be identified with a local inertial frame. In the case of interferometric observations, the measurements are of clock times of arrival of a wavefront at two detectors whose spatial coordinates are specified with respect to instantaneous inertial frames.
A Spectroscopic View of Epsilon Aurigae
Authors: Lambert David L.
Published: June 2019

Spectroscopic observations from the ultraviolet, visible, and infrared obtained at the recent eclipse are discussed. The rotation curve for the disk around the secondary suggests that secondary is a low mass star (or binary). This result with the known mass function suggests that the primary may be a low mass (m1 ≤ the Chandraskehar limit, 1.4 M⊙) star leaving the AGB and evolving to the white dwarf region.
Mass Transfer and Evolution in Long-Period Binary Systems
Authors: Webbink R. F.
Published: June 2019

In the earliest studies of close binary evolution (Paczynski 1967; Kippenhahn, Kohl, and Weigert 1967; Plavec, et al. 1968), it was assumed that the total mass and orbital angular momentum of a binary system are conserved during mass transfer. This assumption of convenience actually succeeds quite well in producing model post-mass-transfer binaries which closely resemble classical Algol-type systems, and helium-star binaries such as KS Per and u Sgr as well (Plavec 1973; Schonberner and Drilling 1983). Among longer-period interacting binaries, however, there are strong reasons to believe that these simple assumptions break down. For example, it is well-known that single stars may lose a very substantial fraction of their mass in a stellar wind during ascent of the giant and asymptotic-giant branches (e.g., Kudritzki and Reimers 1978). In addition, many highly-evolved short-period binaries, such as the cataclysmic variables, appear to owe their origins to very long-period progenitors (Paczynski 1976; Ritter 1976; Webbink 1976). These latter systems evidently evolved through a common envelope phase (Paczynski 1976; Meyer and Meyer-Hofmeister 1979), in which the giant progenitor of the present white dwarf devoured its companion star, and ultimately was divested of its envelope by the release of orbital energy as that companion spiralled toward its core.
Extraction of the Shell Spectrum of Epsilon Aurigae
Authors: Boehm Conrad , Ferluga Steno
Published: June 2019

A sample of high-dispersion optical spectrograms of ε Aur,taken on different epochs before and during eclipse, has been processed by computer in order to extract the shell spectrum, produced by the eclipsing body. Using an uneclipsed spectrum as reference, the primary’s dominant contribution was removed, and this makes it possible for the first time to study the secondary body spectrum separately at all eclipse phases. As the first striking result, one finds that the internal regions of the extended eclipsing body are hotter than the outer zones.
Infrared Michelson Interferometry of Zeta Aurigae Type Supergiants
Authors: Di Benedetto G. Paolo , Ferluga Steno
Published: June 2019

The system parameters of the ζ Aur-type binaries, all containing a cool supergiant and a hot dwarf, have been improved recently by IUE observations (N.P. Schroeder, 1985; A.Ap.147, 103). But the diameters of the supergiant components, determined with different indirect methods, are still discordant. We attempted to solve such discrepancies by measuring directly the angular sizes of these stars, expected to be of a few milli-arcseconds.
Beta Cephei Variables
Authors: Osaki Y.
Published: June 2019

Problems of Beta Cephei variables and of related pulsating B stars are discussed. In particular, various excitation mechanisms of both radial and nonradial oscillations so far suggested are critically examined. The present state of theory for these variables is found unsatisfactory.
Non-Radial Pulsation In Be Stars
Authors: Percy John R.
Published: June 2019

Be stars are B stars in which emission has been observed in at least one hydrogen line on at least one occasion. Some Be stars are pre-main-sequence stars, mass-transfer binaries, or supergiant stars with extended atmospheres. The majority, however, are classical Be stars: single stars on or near the main sequence. An important characteristic of these stars seems to be their rapid rotation – close to but not at the “critical” velocity at which the effective gravity vanishes at the equator.
Cosmic Microwave Background Spectrum Measurements
Authors: Smoot George F.
Published: June 2019

This paper reviews the three major cosmic microwave background radiation (CMBR) spectrum measurement programs conducted and published since the last (XVII) IAU General Assembly. The results are consistent with a Planckian spectrum with temperature 2.72 ± 0.03 K spanning a wavelength range of 0.1 to 12 cm. Limits on possible distortions and implications are outlined. Ongoing and future measurements are discussed.
The Microwave Background from Cambridge
Authors: Saunders Richard
Published: June 2019

Microwave background astronomy has arrived. Largely because of improvements in receivers, the last three years have seen the emergence of agreement concerning important measurements of the microwave background radiation (MBR):

– hard evidence that the MBR has a black-body spectrum (see Smoot in these proceedings);

– the unambiguous detection of the Sunyaev-Zeldovich decrement in clusters of galaxies (Birkinshaw et al 1984), and indeed profiles of the decrement across clusters (Birkinshaw in these proceedings);

– the lack of anisotropy in the MBR temperature T on scales of a few arcmin down to ΔT/T˜5×10-5 (Uson & Wilkinson 1984; Readhead, private communication) and the consequent elimination of simple theories of adiabatic primordial fluctuations.
Abundances of the Very Light Elements (D, 3He, 4He and 7LI) And Primordial Nucleosynthesis
Authors: Audouze Jean
Published: June 2019

The determinations of the primordial abundances of D, 3He, 4He and 7Li play a major role in building up models of Big Bang nucleosynthesis. Much progress has been made recently in that respect but there are still large uncertainties on these determinations. Although canonical Big Bang models predicting a cosmological baryonic parameter ΩB ~ 0.10 consistent with the dynamics of small groups of galaxies and three different families of neutrinos seem to be the most appropriate in accounting for these abundances, the simplest models of galactic evolution lead to discrepant comparisons concerning D and 4He. The relatively small abundance of 4He might challenge the canonical Big Bang models unless specific models of galactic evolution are invoked.
Stellar Dynamo Characteristics
Authors: Weiss N.O.
Published: June 2019

Recent discoveries have shown that magnetic activity is typical of cool stars with deep convective zones and magnetic cycles are found in slowly rotating stars like the sun. The current state of hydromagnetic dynamo theory is reviewed, and simplified models are used in an attempt to isolate the dominant nonlinear processes in stellar dynamos.
On The Rotation-Activity Connection
Authors: Mangeney A.
Published: June 2019

New observations of large scale convection on the Sun challenge the currently accepted dynamo theory of the generation of stellar magnetic field. The available evidence of the correlation between stellar activity and rotation teaches us something about the interaction of rotation with large scale convection. The question of what parameter to use to describe this correlation is discussed.
The Measurement of Stellar Photospheric Magnetic Fields
Authors: Robinson R D
Published: June 2019

The credit for the first detection of magnetic fields on a star belongs to Hale who, in 1908, spectroscopically examined sunspots and determined their Zeeman splitting. Routine measurements of fields, however, did not come until the late 1940’s, with the development of the magnetograph by Babcock. This measurement technique relied on the fact that the split components of a magnetically sensitive line profile had opposite senses of circular polarization. Since the displacement of these components from the central wavelength was directly proportional to the strength of the magnetic field, it was found that the degree of circular polarization measured in the wings of an appropriate spectral line could be directly related to the magnetic flux present within the resolution element, provided the degree of magnetic splitting did not exceed the Doppler width of the line. The technique was applied to the Sun with highly successful results. It was possible to show that the magnetic fields were influential in nearly every form of solar activity. They structured the atmosphere and affected the energy transport, cooling some areas (sunspots) and heating others (e.g., plages and the corona). It was also found that the fields could act as resevoirs of energy. This energy can be explosively released, resulting in flare and mass ejection events.
The Dichotomy between Co Absorptions and ca II Emissions in the Sun and Stars: An Indirect Diagnostic for Gas Disturbed by Magnetic Fields?
Authors: Ayres T.
Published: June 2019

Spectra of the 4.7 μm bands of carbon monoxide in absorption, and spectra of the cores of the 0.4 μm resonance lines of ionized calcium in emission, might be used to diagnose the presence of atmospheric inhomogeneities, caused by the action of surface magnetic fields, on stars as diverse as the Sun and the red giant Arcturus.
Stellar X-ray and Radio Activities and Coronal Magnetic Field
Authors: Uchida Yutaka
Published: June 2019

Activities due to the magnetic effects in the stellar atmospheres are discussed with a special emphasis on the enhanced X-rays and radio activities in RS CVn binaries. Enhanced activities in these close binary systems are proposed to be due to an enhanced production of the twist of the subphotospheric magnetic flux tubes by the large differential rotation in radius, created between the inertially rotating core and more or less synchronously rotating envelope. The magnetic twist of the emerged flux tubes in the “active-longitude-belt” will be dynamically released into inter-star flux tubes together with the driven-out mass heated in the events of magnetic reconnections which are mediated by the magnetic fields of the companion star.
Recent Optical Observations of Supernovae
Authors: Filippenko Alexei V.
Published: June 2019

This paper reviews some of the basic optical properties of supernovae (SNe), concentrating on the most interesting new observations. It is emphasized that SNe can be securely subdivided into the two well-known classes (Type I and Type II) only on the basis of their spectra, since the light curves alone can be misleading. Brief interpretations of the spectra and light curves are presented. Spectroscopic and photometric characteristics of “peculiar” Type I supernovae (SNe I-pec), which may be physically distinct from “normal” SNe I, are discussed. Finally, the complete optical spectrum of SN 1985f in NGC 4618 is illustrated, and comparisons are made with the spectra of SNe I and SNe II. No resemblance is found, suggesting that this object belongs to a truly new class (Type III) of SNe. There is, however, very recent evidence that the spectra of SNe I-pec obtained more than eight months past maximum brightness are strikingly similar to that of SN 1985f.
Phase Transitions of Superdense Matter and Supernova Explosion
Authors: Sato Katsuhiko , Takahara Mariko
Published: June 2019

Effects of the phase transitions of superdense matter on supernova explosions are investigated with the aid of an idealized model of phase transition. It is found that in the case of strong phase transitions explosions become weaker, while in the case of weak phase transitions explosions become stronger, but the increment of the ejectecd energy is less than 20 percent and is not large as suggested by Migdal et al.
X-Ray Emission from Supernova Remnants
Authors: Aschenbach B.
Published: June 2019

A brief review of the observations of X-ray emission from supernova remnants is presented including the results from the Einstein, EXOSAT and TENMA satellites. The status of the interpretation of the spectra and images is highlighted and the need for broad band, spectrally resolved imaging measurements is emphasized.
The Sources of Major Heliospheric Disturbances
Authors: Hewish A.
Published: June 2019

Observations of interplanetary scintillation on about 900 sources made with the 3.6 hectare array at Cambridge have been used to map, and to track, 96 heliospheric transients during August 1978–September 1979. This sample included most of the interplanetary shocks recorded by near-Earth spacecraft in the same period.

Some corotating interaction regions were observed but the most frequent disturbances were “erupting streams” in which spherical shells of enhanced density were driven by the birth of high-speed solar wind streams which persisted for several days. Although these transients were of the type traditionally associated with solar flares or disappearing filaments they were not caused by such processes. Back-projection to the Sun indicated that the sources were always associated with coronal holes. It is concluded that the sources of the most energetic interplanetary transients are mid-latitude coronal holes which, near solar maximum, produce sporadic high-speed streams lasting several days, in contrast to the more stable flows typical of the declining phase of the solar cycle.
The Response of Microwave Emission to the Development of Active Regions
Authors: Smolkov G. Ya.
Published: June 2019

As is known from eclipse observations, the microwave emission of an active region consists of three main components: floccular, inter-spot (halo) and spot components which differ in intensity, the degree of polarization, and in structure and sizes /1/. A possibility of identifying the finer spatial and temporal structure in the active region (AR) emission has existed since RATAN, the VLA and WSRT became operational. The construction of the SSRT permitted the initiation of a systematic study of spatio-temporal properties of the development of active regions /2, 3/.

The majority of the properties in the AR development are reflected in detail and rapidly in the microwave emission characteristics /4, 6/.
Joint Summary Report of the IAU/IUGG Working Groups on the Rotation of the Earth and the Terrestrial Reference System
Authors: Wilkins G. A. , Mueller I. I.
Published: June 2019

The Working Group on the Rotation of the Earth was established in 1978 and developed a programme of international collaboration to Monitor Earth-Rotation and Intercompare the Techniques of observation and analysis (MERIT). The MERIT Short Campaign was held in 1980 to test and develop the organisational arrangements required during the MERIT Main Campaign in 1983-4. The Working Group on the Terrestrial Reference System was established in 1980 to prepare a proposal for the establishment and maintenance of a new Conventional Terrestrial Reference System (COTES) that would be based on the new techniques of space geodesy. The Working Groups collaborated closely and organised two intensive campaigns in 1984 and 1985 that were aimed primarily at determining the relationships between the reference systems of the six different techniques that were used to determine earth-rotation parameters. Observational data were obtained from 35 countries; analyses and intercomparisons of the results were carried out in 7 countries. The Working Groups reviewed the results at the Third MERIT Workshop and recommended that a new International Earth Rotation Service be set up in 1988 and that it be based on the use of very-long-baseline radio interferometry and both satellite and lunar laser ranging.
Theoretical Stellar Energy Distributions
Authors: Kurucz Robert L.
Published: June 2019

We are working hard to improve model atmospheres because existing models have numerical errors, an unphysical treatment of convection, an inadequate or non-existant treatment of statistical equilibrium, an arbitrarily chosen microturbulent velocity, an arbitrarily chosen helium abundance, and a greatly underestimated line opacity for iron group elements.
Halley’S Comet (Part I): Ground-based Observations
Authors: West Richard M.
Published: June 2019

Since the recovery in October 1982, an extensive, international programme to observe Comet Halley with ground-based instruments has been co-ordinated by the International Halley Watch (IHW), and a comprehensive archive is now in the final phases of preparation. The observations were carried out at more than 150 observatories and with all available methods. A special effort was made to support the space missions during the comet encounters in early March 1986. Whereas the spacecraft provided detailed in-situ measurements over a short time interval, ground-based observers have so far followed the development of the comet over a period of nearly six years, and a number of spectacular events near the nucleus and in the tail have been documented in great detail. These observations still continue. This article gives an overview of the most important results obtained from the ground and also mentions the prospects for further observations with large telescopes during the next years.
“Undisturbed” Evolution in Binaries
Authors: Andersen J.
Published: June 2019

The use of binary systems as tools for testing models for single-star (“undisturbed”) evolution is briefly reviewed. Recent successes and directions for future work are discussed.
Binary Wolf-Rayet Stars
Authors: Hidayat B. , van der Hucht K. A.
Published: June 2019

The distribution of the WR cluster members is interpreted in terms of their association with the galactic spiral-arm pattern. It is suggested that in a limited volume the number fraction of WR binaries is influenced more by magnetic field properties of the spiral arms, than by function of the galactocentric distance.
Concluding Remarks
Authors: Trimble Virginia
Published: June 2019

In one sense our subject is an old one, dating back more than two centuries to the work of John Michell on statistics of visual star pairs. In another sense, it is both young and rapidly growing. The first meeting devoted exclusively to binary systems took place in 1966 in Uccle, Belgium, followed by the first IAU Joint Discussion on the subject in 1967 and IAU Colloquia 6 and 18 in 1969 and 1972. From this average of less that one meeting with published proceedings per year, our gatherings have proliferated to about five per year in the mid 80’s. I am inclined to suspect that the topic of formation and evolution of binary stars is now too broad to fit into any one meeting, room, day, or mind.
Effects of the soft X-ray burst from SN 1987A on its circumstellar medium
Authors: Lundqvist Peter , Fransson Claes
Published: June 2019

The observations of the narrow UV and optical emission lines from SN 1987A are modelled as reprocessed radiation in a shell around the supernova, heated and ionized by the soft X-ray and EUV radiation at the shock breakout. Constraints on the early soft X-ray burst are discussed, as well as the physical conditions and abundances in the shell.
What are Families of Minor Planets?
Authors: Kozai Yoshihide
Published: June 2019

This paper describes how the families of minor planets were discovered and how minor planets are classified into families and shows several evidences that at least some families were originated by collisions of minor planets. In fact for major families there are much more fainter minor planets than in other regions and when the families were discovered by Hirayama in 1918 only one sixth of the total numbered minor planets belonged to families whereas now more than one third of them belong to the families. It is also emphasized that the classification into the families is theory dependent and that any theory available now is not accurate enough to derive stable quantities for the families to study their origins as the families are usually bounded partly by mean motion and/or secular motion commensurability regions in the phase space.
Comets, Meteorites and Interplanetary Dust
Authors: Brownlee D. E.
Published: June 2019

Cometary debris of all sizes impacts the Earth but it is likely that only particles the size of dust survive atmospheric entry and are collected as meteoritic samples. Conventional meteorites and a substantial fraction of collected interplanetary dust particles appear to be asteroidal debris. Nearly half of the collected interplanetary particles have properties consistent with cometary material and resemble Halley dust that has lost the maiority of its carbon and nitrogen. These particles might be aggregates of presolar grains ana they provide some insight into the properties of interstellar grains.
Cometary Dust and Zodiacal Light Connection
Authors: Dollfus A.
Published: June 2019

Photopolarimetry of P/Halley coma characterizes, in the cloud of dust grains released by the nucleus, the presence of a significant population of large flakes, made of aggregated small and very dark grains. These globules are subsequently transported toward the Sun, with some modifications in texture, and concentrate in the inner part of the Solar System. Comets appear to be the source for the fluffy grains which are observed in the zodiacal light.
Atomic and Molecular Data for Diffuse Cloud Chemistry
Authors: van Dishoeck Ewine F.
Published: June 2019

A brief overview of the procedure for modeling diffuse interstellar clouds is given, and specific needs for atomic and molecular data are pointed out.
Molecules in Circumstellar Envelopes
Authors: Omont Alain
Published: June 2019

The chemistry of circumstellar envelopes around evolved stars is extremely rich, especially for C-rich ones. 34 molecules have been identified in IRC+10216. Recent observations and modeling prove that most of the unstable species are formed by photochemistry in the outer layers of the envelope.
Atomic and Molecular Data for Stellar Physics
Authors: Bell R. A.
Published: June 2019

This paper discusses a number of problems in the field of stellar astronomy which are caused by inadequate kinowledge of atomic and molecular data.
Chemistry in Shocks
Authors: Hartquist T.W.
Published: June 2019

The column densities of interstellar CH+, first detected about fifty years ago, cannot be explained with models of the chemistry in low temperature gas. The resolution of this classic problem is necessary for us to have confidence in our understanding of interstellar chemistry and its role in determining the physical conditions in interstellar clouds and in the utility of molecular abundance measurements as diagnostics. The possibility that the observed CH+ is formed primarily in shocks in diffuse clouds is addressed. The way in which the chemistry affects the structure of such a diffuse cloud shock is also discussed. The analogous chemical influence on the structures of shocks in dense molecular clouds is also considered as is the possibility that gas in some dense molecular clouds passes repeatedly through dynamical cycles and is shocked frequently enough to influence the global chemical structures in those clouds. Some atomic and molecular data needs are mentioned.
Synchrotron Thermal Instabilities and Radio Filaments in the Lobes of Cygnus A
Authors: Bodo G. , Ferrari A. , Massaglia S. , Trussoni E.
Published: June 2019

Recent VLA observations of the lobes of Cygnus A exhibit complex “filamentary” structures, with typical scale width ~ 1 arcsec (Dreher, Carilli and Perley, 1987, Perley, 1987). The filaments appear aligned with the magnetic field, as results from polarization measures, suggesting that the field may play a fundamental role in the process of their formation.

We propose a mechanism for the possible formation of these filaments based upon a thermal instability connected with synchrotron emission from relativistic electrons. This type of instability was studied by Simon and Axford (1967), who discussed it in connection with the Crab Nebula filaments, and by Eilek and Caroff (1979), who generalized the previous study for application to quasar atmospheres.
Coronal Heating: Theoretical Ideas
Authors: Hollweg Joseph V.
Published: June 2019

After four decades of study, the mechanisms for heating the corona are not understood. However, the development of the field is vigorous. A variety of new ideas have been proposed, and these new ideas have generated lively debate. The goal of this short review is to present a broad overview of the ideas currently under consideration.

It is now accepted that the solar magnetic field is the key ingredient. It is not known whether waves are important or not, but it is agreed that the magnetic (and possibly associated kinetic) energy must eventually appear in thin structures so that the (generally weak) dissipative processes can heat the plasma. This poses a problem of how the heat gets distributed throughout the corona.
An Update on X-Ray Emission from Stars
Authors: Rosner R.
Published: June 2019

With the closing of the Einstein and EXOSAT eras, the characteristics of stellar x-ray emission are now fairly well understood. In this very brief review, I will focus on two specific topics central to the physics underlying stellar activity: the rotation-activity connection and the “decay” of activity at the low mass end of the main sequence.
Meter Wave Interferometry
Authors: Swarup G.
Published: June 2019

There are many outstanding astrophysical problems which are best studied at meter wavelengths. However this part of the spectrum has not been fully exploited for astronomical observations for several reasons. Firstly, the arrays at cm wavelengths provide higher resolution. Secondly, the level of man-made radio interference is very high at the longer wavelengths in industrialised countries, although it is not so high in countries such as India. Finally, the phase variations caused by the ionospheric irregularities are quite severe at meter waves, particularly for a large array (~ λ/35 rad.km-1).