bluuebunny/crossref_metadata_2025 huggingface dataset:
Malaya/ Singapore/ Malaysia: Comments on State Competence, Succession and Continuity
Authors: Green L. C.
Published: June 2019

The Constitutional and international history of Singapore and Malaya have been chequered and hectic since the days of the Japanese occupation. Perhaps the most startling were the years from 1963 to 1965, the period during which Singapore ceased being a Crown Colony to form with Malaya the Federation of Malaysia and, when that experiment failed, to become an independent sovereign state within the Commonwealth.

It is the purpose of this paper to examine this history in order to extract those issues which are of interest from the point of view of state succession and the continuity of law, while at the same time paying attention to some of the problems of competence that occur in a federal state, especially one in which the component parts have only recently enjoyed independence.
The Dominican Crisis: An Inter-American Dilemma
Authors: McLaren John P. S.
Published: June 2019

From whatever standpoint it may be viewed, the decision of President Johnson to order the Marines into the Dominican Republic on April 28, 1965, was bound to provide a focus for controversy. However, the essentially political nature of that act and its ostensible and concealed motivations have tended to shroud the impact of the Dominican crisis upon the legal mechanisms of the Inter-American System, outlined in the basic documents and developed in the practice of the Organization of American States. This is not to suggest that the problems of Latin America in general and of the Dominion Republic in particular are reducible to a statement of principles of international law. Indeed, it is the present writer’s contention that the Latin American members of the Organization have demonstrated that they are far too servile towards what they deem to be the basic norms of American international law, and that this attitude coupled with the equivocal political manœuvres of the United States has produced a form of institutional schizophrenia which deflects attention from the basic problems of contemporary Latin America and the pressing need for their solution. The main purposes of this comment are to examine the Dominican crisis in the context of fundamental stresses in Latin American society, to evaluate the roles of the United States and the O.A.S. in terms of their reactions to this case, and to make some general comments on how the Inter-American System may be rendered more meaningful in dealing with the political, economic, and social priorities of the region.
Distinguishing Friend from Foe: Law and Policy in the Age of Battlefield Biometrics
Authors: Mitchell Alison
Published: June 2019

In the space of just over ten years, the collection and use of biometric data in the context of international military operations has gone from being virtually unheard of to being an everyday occurrence. The Canadian and US armed forces operating in Afghanistan, for example, have together collected the digital fingerprints, eye scans, and digital photographs of more than 2.5 million Afghans. The introduction of biometrics technology to warfare has undoubtedly increased the security of the armed forces that use it and made it easier for them to kill or capture their enemies. Its effectiveness, reliability, and convenience have all been praised. Due in part to its novelty, however, law and policy relating to the use of biometrics in conflict situations remain underdeveloped. This underdevelopment poses considerable risks for the already vulnerable populations who are being subjected to these programs, potentially including violations of their right to privacy, misuse of their personal data, or their misidentification as enemies or threats. This article weighs these benefits and risks associated with biometrics technology. It analyzes the extent to which law and policy already govern the collection and use of biometrics by armed forces at both the domestic and international levels. It explores why the United States and Canada — the two states whose armed forces appear to be the most heavily engaged in the collection of biometric data abroad — have adopted such different policies with respect to the use of biometrics. It explains why the current international legal and policy vacuum in relation to battlefield biometrics is unacceptable and concludes that the time to discuss best practices is now. Ten non-legally binding guidelines are proposed for consideration and potential adoption by states.
The Changing United Nations Constitutionalism. New Arenas and New Techniques for International Law-Making
Authors: McWhinney Edward
Published: June 2019

The Advisory Opinion handed down by the World Court on July 20, 1962, concerning Certain Expenses of the United Nations has become a political cause célèbre in so far as the majority judicial position in it was backed up by the Western-sponsored action, in terms of Article 19 of the United Nations Charter, to deprive the Soviet Union and France of their vote in the General Assembly. The Advisory Opinion of the World Court has, however, its own intrinsic interest in terms of juristic method and of basic Soviet and Western differences in scientific approach to law. In his dissenting, judicial opinion in that case, the then President of the Court, the Polish jurist, Judge Winiarski, formulated principles of interpretation which reveal, very dramatically, the basic doctrinal differences between Soviet bloc and Western jurists as to the nature and character of the Charter. As President Winiarski commented:

The Charter has set forth the purposes of the United Nations in very wide, and for that reason too indefinite, terms. But… it does not follow, far from it, that the Organisation is entitled to seek to achieve those purposes by no matter what means. The fact that an organ of the United Nations is seeking to achieve one of those purposes does not suffice to render its action lawful. The Charter, a multilateral treaty which was the result of prolonged and laborious negotiations, carefully created organs and determined their competence and means of action.
New States, Regionalism and International Law
Authors: Green L. C.
Published: June 2019

Traditionally, international law has come to be regarded as consensual in nature, depending for its authority upon the recognition and acceptance of those entities which it seeks to bind. This view was accepted by the Permanent Court of International Justice in the S.S. Lotus: “The rules of law binding upon States emanate from their own free will as expressed in conventions or by usages generally accepted as expressing principles of law and established in order to regulate the relations between these co-existing independent communities or with a view to the achievement of common aims.” Article 38 of the Statute of the World Court, when listing the “sources” of international law, also acknowledges its consensual basis. In its substantive portion the article refers to conventions “establishing rules expressly recognized by the contesting States.” It then refers to custom “as evidence of a general practice accepted as law,” which has been explained by the International Court of Justice in the Asylum Case: “The Party which relies on a custom … must prove that this custom is established in such a manner that it has become binding on the other Party. [It] must prove that the rule invoked by it is in accordance with a constant and uniform usage practised by the States in question, and that this usage is the expression of a right appertaining to the [one] State … and a duty incumbent on the [other] State.”
South West Africa Cases Ethiopia v. South Africa; Liberia v. South Africa Second Phase
Authors: Flemming Brian
Published: June 2019

A first reading of the majority opinion in the South West Africa Cases, Second Phase, may leave the Common Law reader with the feeling of having waded through the marshes of a pre-Judicature Act search for a form of action in which to frame this case; the plaintiff having failed to find the proper writ, the defendant's demurrer is thereby upheld. The extremely technical, indeed artificial, nature of the International Court of Justice's judgment of 1966 has already stirred controversy, but one suspects that the heat of debate will cool rapidly out of sheer frustration with this judgment. Many writers will assume the attitude of Judge Wellington Koo who said in his dissenting opinion that “There is a Chinese proverb put in the form of a question: Why write a long and big essay on such a small subject?” In labouring to bring forth its largest judgment yet (500 pages), the International Court of Justice has engaged in what Judge Jessup, in his excellent dissenting opinion, called a “procedure of utter futility.”
Certain aspects de l’évolution récente du problème de l’immimité de juridiction des Etats
Authors: Vincke Christian
Published: June 2019

La Question de l’immunité de juridiction des Etats étrangers est particulièrement liée au rôle joué pas les Etats tant dans le domaine interne qu’international. Il est devenu banal de dire que les activités étatiques ont envahi, depuis le début de ce siècle, des domaines considérés jusqu’alors comme étant réservés a l’initiative de personnes ou institutions strictement privées. Les conséquences de ce changement sont importantes. A ce point même que sur le plan interne beaucoup d’Etats ont eu à faire face à des problèmes de réaménagement de leurs structures qui, conçues dans une autre époque, n’avaient pas prévu le montée extraordinaire de l'Exécutif au détriment du Pouvoir législatif.
Exemption from the Jurisdiction of Canadian Courts
Authors: Castel J.-G.
Published: June 2019

I Persons against whom the jurisdiction cannot be enforced

The first part of this note deals with the persons who claim immunity from the compulsory jurisdiction of Canadian courts.

(1) The Foreign State, Sovereign or Head of Foreign State as a Defendant

The law relating to the immunity of foreign states and sovereigns or heads of foreign states from Canadian jurisdiction is to be found in the common law and has been stated and re-stated in leading cases such as The Parlement Belge, The Porto Alexandre, The Cristina, Dessaulles v. The Republic of Poland and Mehr v. The Republic of China et al. Lord Atkin reduced this law to two propositions:

The first is that the courts of a country will not implead a foreign sovereign, that is, they will not by their process make him against his will a party to legal proceedings whether the proceedings involve process against his person or seek to recover from him specific property or damages.

The second is that they will not by their process, whether the sovereign is a party to the proceedings or not, seize or detain property which is his or of which he is in possession or control.
The Guatemala City Protocol to Amend the Warsaw Convention
Authors: Fitzgerald Gerald F.
Published: June 2019

The International Conference on Air Law, convened under the auspices of the International Civil Aviation Organization, met in Guatemala City from February 9 to March 8, 1971, and adopted a Protocol to Amend the Convention for the Unification of Certain Rules Relating to International Carriage by Air Signed at Warsaw on October 12, 1929, as Amended by the Protocol Done at The Hague on September 28, 1955. The Protocol greatly revised the legal rules governing the international carriage by air of passengers and baggage.
Approaches to the Law of Armed Conflict
Authors: Morley Jeremy D.
Published: June 2019

The international legal framework has traditionally been divided into a “state of war” and a “state of peace.” Most contemporary authorities still insist upon sharp and tidy categorization in this area, although some would prefer a three-fold or a multi-fold division, instead of the standard two-fold split. This whole approach has come under attack in recent years.

A division into “states” of “war” and “peace” should theoretically produce simplicity and clarity. Instead, however, it leads to hopeless complications. This is clear as soon as any attempt is made to define the “state of war.”
Legal Limits on the Use of Force by Canadian Warships Engaged in Law Enforcement
Authors: Fenrick W.J.
Published: June 2019

Warships are designed for fighting in war. In peacetime, the primary task of warships and of their crews is to prepare for war. At the same time, because they are a visible embodiment of force, they may, at the pleasure of the executive, be employed on other tasks where the display of force is useful, such as the protection of sovereignty or the enforcement of laws both domestic and international. Some countries — the United States is an example — as a matter of principle, do not use warships to assist in the enforcement of national laws. Others, such as the United Kingdom and Canada, do use warships for such tasks. As a matter of practice, however, Canadian warships are rarely used for law enforcement against Canadian vessels.
The Scottish Tradition in International Law
Authors: Johnston Douglas M.
Published: June 2019

There has never been a Scottish school of international law. The concept of a “school” might, of course, be accorded a number of different meanings, but in any official sense the Scottish nation was never in a position to adopt a distinctive approach to international law. The union of the Scottish and English crowns (1603) and legislatures (1707) curtailed the opportunity for Scottish customs to be put forward as the evidence of national state practice. Moreover, it is difficult to show a critical mass of Scottish contributions to the subject, sufficient to form the basis for a national school of international legal theory. Indeed, in the 300 years up to World War I Scotland produced only a handful of significant contributions to the literature of international law: pre-eminently, William Welwood (1578-1622), William Scott (1674-1725), Sir James Mackintosh (1765-1832), James Reddie (1773-1852), James Lorimer (1818-90) , Viscount Finlay of Nairn (1842-1929) , Arthur Berriedale Keith (1879-1944), and Thomas W. Fulton ( 1855-1929).
Choice of Law Methods in the Private International Law of Contract
Authors: Blom Joost
Published: June 2019

For anyone who is interested in the methodology of choice of law, no field is more rewarding than that of contracts. As domestic laws of contracts develop a progressively more intricate relationship between the principles of social regulation and private autonomy, private international law is led to develop choice of law techniques that will keep an appropriate balance between these principles in interjurisdictional cases. Choice of law rules that underemphasize the interests of the parties, and rely instead on the regulatory concerns of states that are affected by the transaction, may place too many obstacles in the way of persons who should be left to arrange their transaction in the way they think best. At the same time, choice of law rules that give too much weight to the parties’ wishes may interfere unduly with a state’s ability to regulate a transtaction with which it has a legitimate concern. In this respect, balance is more difficult to achieve in contracts than it is elsewhere.
The Legal Status of the International Joint Commission under International and Municipal Law
Authors: Wex Samuel
Published: June 2019

The international joint commission bas historically possessed the characteristics of an international organization; by reason of the capacities that it exercises, it has a certain measure of international personality; and, consequently, on the municipal plane, it has the capacity to be sued. It is therefore necessary, on the principle of effectiveness, that the Commission and its employees be immune from suit. In the United States, the Commission and its employees were granted immunities in 1948. In Canada, the Commission alone was granted immunities in 1976. It will be argued here that immunities should now also be granted to all commissioners, staff, and experts in Canada, in view of the standing of the Commission as an international organization possessing international personality, with consequences for municipal law.
A Search for Variations in the Intensity of the Optical Pulses from NP 0532
Authors: Hegyi D. , Novick R. , Thaddeus P.
Published: June 2019

A search for short-time variability of NP 0532 using the 82 and 107 in. telescopes at McDonald Observatory is described. Observations were made of the mean intensity, the mean square of the intensity and the mean autocorrelation function of the pulsar light. Limits are placed on the variability of the optical pulsar.
Magnetism in white Dwarfs
Authors: Landstreet J. D. , Angel J. R. P.
Published: June 2019

Searches have been made for the normal and quadratic Zeeman effect and broad-band circular polarization in white dwarf stars. A positive effect has been found in Grw + 70°8247 whose continuum shows both linear and circular polarization.
Cassiopeia A – the Youngest Known Galactic Supernova Remnant
Authors: van den Bergh Sidney
Published: June 2019

Proper motion observations show that the explosion of the Cas A supernova took place in AD 1667 ± 8 (me). Individual moving knots have lifetimes ~ 10 yr. In these fast-moving knots oxygen and argon are overabundant by a factor of at least seventy with respect to hydrogen and nitrogen. Nitrogen is found to be overabundant in quasi-stationary flocculi. This suggests that these flocculi were formed from material that was ejected from the outer layers of the pre-supernova before its explosion in AD 1667.
Models of Rotating Neutron Stars in General Relativity
Authors: Bonazzola S. , Maschio G.
Published: June 2019

We describe a numerical method of integration of Einstein's equations coupled with the hydrodynamic equations for a perfect fluid. We give, also, some preliminary results.

We point out that the analogous problem was considered by Ostriker and Mark (1968) in the Newtonian case; by Thorne (1969) in General Relativity, in the weak angular velocity approximation; by Barden and Wagoner (1969) for disk configurations in the pressure vanishing case.
Periodicity and Luminosity of the ‘Pulsar’ Model of Quasars
Authors: Fowler William A.
Published: June 2019

The diagnosis of pulsar-like symptoms in the quasar 3C 345 has renewed interest in differentially rotating supermassive stars (SMS). Quasi-periodic behavior follows from differential rotation. In reviewing early work on this quasar model it is found that SMS models with rotational periods of the order of a few hundred days and with pulsation periods approximately one-quarter as long can supply thermal and magnetic dipole radiation of the order of 1048 erg sec-1 for somewhat more than 106 yr. The surface field required for the magnetic dipole radiation is approximately 103 G. The SMS mass taken as typical in the calculations is 3 × 109M⊙.
Multiple Pulsar Ejection in Supernova Events
Authors: Curtis Michel F.
Published: June 2019

Fragmentation in the collapse of a supernova core, followed by energy loss in neutron star formation, is shown to lead to disruption of the resulting system. The elements of the system, some of which should be pulsars, can attain velocities of the order of 103 km/sec if currently quoted parameters are correct.
Relationship Between Pulsar and Nebula
Authors: Woltjer L.
Published: June 2019

The magnetic field and the relativistic electrons in the Crab Nebula cannot have originated at the time of the supernova explosion. The energy density in the magnetic field is so large that it must have been generated using the energy supply in the pulsar. The energies of the electrons are so high, and their lifetimes correspondingly are so short, that they must have been accelerated, again using the pulsar energy. The efficiency of these processes must be high, but there is an adequate energy supply.
Radiation Beaming in Pulsars
Authors: Canuto V.
Published: June 2019

It is usually considered that the beaming of the radiation coming out of a pulsar has to be strictly connected with the mechanism producing the radiation itself. We want to show that even when the emitting mechanism gives rise to an isotropically distributed radiation, the presence of a strong magnetic field will automatically beam the radiation preferentially along the magnetic field line rather than in any other direction. We have computed the Compton scattering and from that the opacity KH (K0 is the opacity for zero field). In Figure 1 the ratio KH/K0 is given vs. θ, the angle between the propagation vector and the magnetic field axis. Hq is a critical magnetic field numerically equal to 4.41 × 1013 G; Ne is the electron density. For the ordinary wave the opacity is reduced at θ = 0, while it is unaffected at θ = π/2 where KH → K0. Even at θ = π/4 the ratio KH/K0 is still ≃ 10−2, and a good beaming is still present. The values of the parameters are proper for a neutron star surface. It is to be noticed that the ratio KH/K0 is of the order of (ω/ωH)2 or [(kT/mc2)/(H/Hq]2. One therefore can conclude that the presence of a magnetic field itself assures the beaming of radiation along the field lines.
On the Strength of the Galactic Shock Wave and the Degree of Development of Spiral Structure
Authors: Roberts William W. , Roberts Morton S. , Shu Frank H.
Published: June 2019

The luminosity of a spiral arm is believed to originate primarily in the very young, newly forming stars; and the spiral arm itself to be a spiral wave which is capable of triggering the formation of the young stars selectively along the wave crest. A semi-empirical study of the density wave patterns predicted in the density wave models of twenty-five external galaxies has been made and one result of this study is presented here. It is found that those galaxies of the sample whose models predict the possibility of strong shock waves are also the galaxies which exhibit long, well-developed spiral arms; and those galaxies whose models predict weak shock waves are also the galaxies which exhibit less-developed spiral structure. This trend is seen through a correlation between w⊥0, the velocity component of basic rotation normal to a spiral arm, which is an important parameter in determining the shock strength on the one hand, and luminosity class, which is a measure of the degree of development of spiral structure on the other.
Resonant three-wave interactions and an application to solar g mode oscillations
Authors: Guenther D. B. , Demarque P.
Published: June 2019

We present here some initial results of a long-term investigation of resonant three-wave interactions in the solar interior, which indicate that these nonlinear interactions take place in the sun and are, in fact, responsible for the observed g mode spectrum. Resonant three-wave interactions, as the name implies, involve the coupled interaction of three waves which satisfy the resonant condition
where ω0, and ω1 are the frequencies of the three waves. Two of the waves, mode 0 and 1 for example, couple together to produce a third beat wave which has a frequency equal to the frequency difference of the first two waves. This wave is normally very weak. If its frequency happens to equal the frequency of an oscillation mode of the sun, the wave can be pumped by resonance to very large amplitudes. In the sun, resonant interactions would take place if three natural oscillation modes of the sun satisfy the resonance condition.
Convective motions as an indicator of solar structure
Authors: Van der Borght R. , Fox P.
Published: June 2019

Most stars contain regions which are convectively unstable and one of the more daunting tasks facing astrophysics today is to find a satisfactory theoretical formulation of turbulent energy transport in stars. Various theories have been proposed, such as the mixing-length formalism and its extensions, and it would be most useful if one could test the accuracy of such models in view of their importance in the theory of stellar structure and evolution.
Intermediate mass stellar models: Ages of Magellanic Cloud star clusters
Authors: Flower Phillip J.
Published: June 2019

Ages of six intermediate-age Large Magellanic Cloud star clusters have been estimated using the time dependent behavior of the luminosity of stellar interior models of red giants. All clusters studied, NGC 1783, NGC 1868, NGC 1978, NGC 2121, NGC 2209, and NGC 2231, were found to have ages < 109 yr. It is concluded that there is currently no substantial evidence for a major cluster population of large, populous clusters > 109 yr in the Large Magellanic Cloud.
Comparisons between observational color-magnitude diagrams and synthetic cluster diagrams for young star clusters in the Magellanic Clouds
Authors: Becker Stephen A. , Mathews Grant J. , Brunish Wendee M.
Published: June 2019

Young star clusters (<3 × 108 yr) in the Maqellanic Clouds (MC) can be used to test the current status of the theory of stellar evolution as applied to intermediate and massive stars. The color-magnitude diagram of many young clusters in the MC shows, unlike the case of clusters in our Galaxy, large numbers of stars in both the main sequence and post main sequence evolutionary phases. Usina a arid of stellar evolution models, synthetic cluster H-R diagrams are constructed and compared to observed color-magnitude diagrams to determine the age, age spread, and composition for any given cluster. In addition, for those cases where the data is of high quality, detailed comparisons between theory and observation can provide a diagnostic of the accuracy of the stellar evolution models. Initial indications of these comparisons suggest that the theoretical models should be altered to include: a larger value for the mixing length parameter (α), a larger rate of mass loss during the asymptotic giant branch (AGB) phase, and possibly convective overshoot during the core burning phases.
Constraints on terminal AGB evolution from properties of Miras and OH-IR sources
Authors: Willson L. A. , Bowen George H.
Published: June 2019

Near the tip of the AGB we find the optical Mira variables and also the OH-IR stars. Observational data on the luminosities, periods, and population membership of the OH-IR sources are beginning to be available; in principle this information should constrain AGB models very strongly. In practice, current data are found to be insufficient to unambiguously determine the relation between Miras and these sources; in fact three very different interpretations are currently possible.
Some observable indicators of

s

-process environments?
Authors: Despain Keith H.
Published: June 2019

By definition, the chemically peculiar stars have element abundances that are non-solar. Many of these stars show peculiarities in s-process elements. This paper discusses observable indicators of the neutron environment for the s-process in these stars.
Evolution of S stars in the magellanic clouds
Authors: Lloyd Evans T.
Published: June 2019

Early S stars occur between M and C stars in the colour magnitude diagrams of intermediate age globular clusters in the Magellanic Clouds. Most have −4.2 ≥ Mbol ≥ −4.8 and are probably brighter in younger or more metal rich clusters. The galactic globular cluster NGC 6723 contains two marginal S stars at Mbol ∼ −3.3. The rare CS stars have Mbol ∼ −6, with no faint examples.
Mass loss from highly evolved stars
Authors: Hamann Wolf-Rainer
Published: June 2019

This is a summarizing discussion about detailed studies of stellar winds from hot, subluminous stars of different classes: two sdO's (Hamann et al., 1981), three extreme helium stars (Hamann et al.,1982) and one CPN (Hamann et al.,1983). All program stars have been analyzed previously in Kiel by non-LTE techniques with respect to effective temperature, gravity and abundances. For comparison, we have also included the Of-supergiant Pup and the B-main sequence star Sco, because their winds have been investigated in detail by the same methods as applied in this paper (Hamann, 1980, 1981).
Ultraviolet spectral morphology of on and OC stars
Authors: Walborn Nolan R. , Panek Robert J.
Published: June 2019

We have undertaken a systematic survey of 115 0-B0 type spectra between 1200 and 1900å, by means of International Ultraviolet Explorer high-dispersion data rebinned to a constant wavelength resolution of 0.25å and uniformly normalized (Walborn and Panek 1983). The ultraviolet spectral features, both photospheric and stellar wind, are found to be smoothly correlated with the optical spectral types for the majority of normal stars. In particular, the C IV (λλ1548,1551) and N V (λλ1239,1243) resonance doublets show similar strong P Cygni profiles, which decline along the main sequence beginning at type 07 but remain strong in all higher luminosity spectra. In contrast, the stellar wind effect in the Si IV (λλ1394,1403) doublet displays a pronounced luminosity dependence, being absent from the main sequence spectra at all types and developing gradually through the intermediate luminosity classes into a full P Cygni profile in the supergiants. Relative to this consistent framework provided by the normal stars, a number of peculiar spectra can be succinctly described, including several of types OBN and OBC (Walborn 1976).
On the hydrogen abundance in Wolf-Rayet stars
Authors: Schmutz Werner
Published: June 2019

With a semiempirical NLTE-model in spherical geometry we investigate the hydrogen abundance in Wolf-Rayet stars. We find that the flux contribution of the H-Balmer to the He-Pickering lines lies between the usually applied approximate formulae for the optically thin and optically thick case. This result can be understood with our finding that there are no optically thin helium and hydrogen lines. The influence of the temperature structure on the relative intensity of the hydrogen-helium blends to the helium lines is vanishingly small, even for peculiar temperature laws. The conclusion is that Wolf-Rayet stars are hydrogen deficient objects.
Further candidates of supermassive stars in other galaxies
Authors: Schmidt-Kaler Th. , Feitzinger J.V.
Published: June 2019

To look for other supermassive stars in other galaxies means to answer the question: what is the spectroscopic and morphological signature of such objects? The interpretation of WR sources found in other supergiant HII complexes depends basically on our picture of 30 Dor and in particular of R136a.
Evolution of massive stars with mass loss: Surface abundances
Authors: Greggio Laura
Published: June 2019

The location of theoretical stellar models in the upper part of the HR Diagram (HRD) depends on a variety of poorly understood physical proc esses which may occur during the evolution of massive stars. Among the most important we find: mass loss, convective overshoot and opacity enhancement for temperatures around 106 °K. The effects of these phenomena have been recently investigated by several authors (Bertelli et al. 1983 and references therein), but, due to the large uncertainties still present in the theoretical formulation of these processes, only parametrized formulae are avaliable for model computations. Since the theoretical dis tribution of massive stars in the HRD turns out to be fairly sensitive to these parameters, the evolutionary scenario for massive stars is still far from being satisfactorily settled. On the other hand, due to mass loss, nuclear processed material is expected to be exposed at the surface of massive stars and then, the comparison between theoretical predictions and observations of the surface chemical composition of these objects can help in understanding their evolution and to set more stringent limits to the mentioned parameters.
Ages, age differences, masses of stars in young open clusters
Authors: Jakobsen Anne Marie
Published: June 2019

An extensive amount of accurate uvby Hβ data has been obtained for stars in young open clusters. Age spread earlier found within the clusters has been confirmed. Many unevolved stars have been observed. The data for these stars are positioned below ZAMS curves in HR diagrams defined by the Strömgren indices. These unevolved stars form a confined lower envelope for all the stars a little below the “normal” ZAMS curves.
Apsidal motion in main-sequence binary stars
Authors: Jeffery C. Simon
Published: June 2019

Early studies of apsidal motion in binary stars showed a marked discrepancy between observational results and theoretical expectation (Schwarzschild, 1958; Kopal, 1965). Improvements in theory (Petty, 1973; Odell, 1974; Stothers, 1974) have led to much closer agreement. However, recent observational results (Giménez & García-Pelayo, 1982; Monet, 1980) have provided much more data with which to test theoretical results.
Double-mode RR lyrae stars in the Draco dwarf galaxy and in other stellar systems
Authors: Nemec James M.
Published: June 2019

Eleven double-mode (dm) RR Lyrae stars, with periods midway between the periods for the c-type and ab-type RR Lyrae stars, have been identified in the Draco dwarf galaxy by reanalyzing the photometry of Baade and Swope (1961) for 35 stars. The stars are V11, 72, 75, 83, 112, 138, 143, 156, 165, 169 and 190, three of which previously were noted as dm RR Lyraes by Goranskij (1982). The methods of Stellingwerf (1978) and Stobie (1970) were used to find the periods. The period ratios, periods and amplitudes suggest that the stars radially pulsate simultaneously in the fundamental and first overtone modes. The beat masses, estimated from the P1/P0 vs. P0 diagram (Petersen 1973), using as calibration the King Ia (Y=0.299, Z=0.001) models of Cox, Hodson and Clancy (1983, hereafter CHC), are Mbeat/Mo=0.65 for nine stars, = 0.60 for V75 and = 0.55 for V165. If the mass loss rate prior to arriving on the horizontal branch is proportional to the metal abundance (Stobie 1971, CHC), V75 and V165 should be more metal rich than the other nine dm RR Lyraes. In the period-amplitude (P-A) diagram, at a given amplitude, V165 has a smaller period shift relative to the standard M3 line than do the higher mass stars. Subsequently, the correlations of Preston (1959) and Sandage (1982) suggest that it is more metal-rich than the other nine dm RR Lyrae stars in Draco. Furthermore, reanalysis of the P-A and period-mean magnitude relations of all the RR Lyrae stars in Draco shows evidence for a widespread range in the metal abundances. Stars with large period shifts relative to the M3 relation are found to be more luminous than stars with smaller period shifts. The frequency of variable amplitude (ie. Blazhko effect) RR Lyrae stars is greatest for the ab-type stars with short periods. The brightnesses of the highest maxima appear to fit the P-A relation, and the amplitudes of the lowest maxima are variable, with V123 being an extreme example. Figure 3 of Szeidl (1975) shows the analogous situation for M3 RR Lyrae stars with the Blazhko effect. These findings suggest that the amplitude variability is related to the mode-switching activity of the dm RR Lyrae stars.
Lithium abundances in late main sequence stars. The case of the hyades
Authors: Baglin A. , Morel P.J.
Published: June 2019

It is well known that light elements like lithium are good indicators of the hydrodynamical behaviour of the outerlayers of the stars. As they are nuclearly destroyed at low temperature, i.e. close to the surface, their surface abundances reflect the nature of the transport process at work between the photosphere and the nuclear destruction region.
A random walk approach to the problem of turbulent diffusion and lithium destruction in main sequence stars
Authors: Cayrel Roger
Published: June 2019

It has been suggested by Schatzman (1977) that the empirical lithium content/age relationship found by Herbig (1965) could be explained by exchange of matter between the convective zone and deeper layers, where the rate of lithium burning is higher, by turbulent diffusion. The claim by Tassoul and Tassoul (1983) that such a turbulence is necessary to obtain a self-consistent description of stellar rotation and meridional circulation has given some momentum to Schatzman's proposal, as well as other successes of the turbulent diffusion hypothesis (Schatzman et al. 1981).
The Specification of Nutation in the IAU System of Astronomical Constants
Authors: Wilkins G. A.
Published: June 2019

The principal purpose of the IAU system of astronomical constants is to provide a self-consistent set of constants for use in the computation of the international ephemerides of the Sun, Moon, planets and stars and in the reduction of observations of these bodies. At present nutation is computed from a theory of the rotation of the Earth as a rigid body and only the coefficient of the principal term in obliquity is specified in the system of constants. Such a simple specification will not be adequate for use with the more precise observations that are becoming available, and it appears that it will be necessary to adopt a new model of the Earth and to develop a new theory of nutation which will take into account the elastic properties of the Earth. The new model should be consistent with other constants of the IAU system, and with the model used in other branches of geophysics. The new specification of nutation should be formally adopted by the IAU in 1979 so that it can be used in the published ephemerides for 1984 onwards.
Nutation and Nearly Diurnal Latitude Variations from the Data of Bright Zenith Star Observations in Poltava from 1950 to 1977
Authors: Popov N. A. , Yatskiv Ya. S.
Published: June 2019

The observations of bright zenith stars (α Persei and η Ursae Maj) have been carried out in Poltava since 1939. These observations have been used for determining the corrections to semiannual and fortnightly nutation terms and for studying the nearly diurnal free polar motion (Popov, 1968; Popov and Yatskiv, 1977). Recently the reduction of the new series of bright zenith star observations has been finished in Poltava (see Table 1). Therefore it was interesting to carry out a new analysis of these observations for the purpose of studying the nutation and of searching for the nearly diurnal free polar motion.
Recherche de Termes de Nutation dans l'Analyse des Observations de Latitude Effectuées à Paris
Authors: Capitaine N. , Chollet F. , Débarbat S.
Published: June 2019

Les données utilisées dans ce travail sont les observations de latitude couvrant une durée de vingt années (1956 a 1976). Le programme d'observation est resté inchangé et les réductions ont toutes été effectuées dans le Système du FK4 et des Constantes adoptée par l'UAI en 1968.
Spectral Analysis of Latitude Observations at Gorky and Determination of the Semi-Annual Term of Nutation
Authors: Kovbasjuk L. D.
Published: June 2019

The problem of diurnal latitude variations is very closely connected with such fundamental questions as the causes of the closing sum, making more precise the coefficients of the forced nutation terms, study of the diurnal free nutation, etc.
A Review of the Different Liquid Core Models Used for the Computation of the Dynamical Effects on Nutations and Earth Tides
Authors: Melchior P.
Published: June 2019

Note: This short review was given during the Symposium at the request of a number of participants to serve as an elementary introduction to the discussion of the results obtained from different Earth models. It was not prepared in advance and is not an original contribution.

The first approximation of the figure of a fluid planet is obtained by assuming hydrostatic equilibrium with respect to its gravitational self-attraction and the centrifugal force. When the speed of rotation is not too fast, the equipotential surfaces may be considered to an excellent approximation as ellipsoids of revolution. It is easy to show that these hydrostatic equipotential surfaces are surfaces of equal density (p).
Gravitational, Inertial and Toroidal Oscillations of the Outer Core and Their Related Free Wobbles
Authors: Shen Po-Yu
Published: June 2019

According to the respective restoring forces of self-gravitation, Coriolis force, and inertial coupling at the boundaries, the free oscillations of a contained fluid can be classified into gravitational, inertial, and toroidal oscillations. For the outer core of the Earth, however, due to the interplay of rotation, elasticity, and self-gravitation, the gravitational undertones and inertial oscillations are not distinguishable. Both have eigenfunctions consisting of spheroidal and toroidal parts of about equal amplitude, and exist in alternating allowed and forbidden zones depending on the gravitational stability of the outer core. The forbidden zones for a stable core correspond to the allowed zones for an unstable core, while for a neutrally stratified core there appear to be no forbidden zones. The eigenfunction of a toroidal mode consists essentially of a primary toroidal field and a secondary spheroidal component of the order of ellipticity, coupled at the outer core-mantle or outer core-inner core boundary. Therefore, in general, toroidal core modes appear in doublets Sn+1m Tnm and Sn−1m Tn−1m with degenerate frequency equal to 2m/n(n+1) times the angular frequency of rotation of the Earth. The ellipticities of the outer core boundaries are responsible for the removal of the degeneracy. It is shown that the primary toroidal and secondary spheroidal fields constitute the “generalized Poincare motion” which, for the fundamental mode S21T11, reduces to the “simple motion” defined by Poincare in 1910. Numerical solutions have been obtained for all three types of free core modes. While those for gravitational undertones and inertial oscillations are obtained by arbitrarily truncating the hydrodynamic equations, it is shown that the eigensolutions for toroidal modes are correct to first order in ellipticity due to the particular geometry of the outer core of the Earth.
Earth Tide Components and Forced Nutations
Authors: Melchior P.
Published: June 2019

The relation between the Earth tide components and the forced nutations has been demonstrated in detail in previous publications (Melchior and Georis 1968, Melchior 1971,1973,1976,1977). We will therefore restrict the development to the essential formulae.
CO Observations of M51
Authors: Rydbeck G. , Pilbratt G. , Hjalmarson Å. , Olofsson H. , Rydbeck O. E. H.
Published: June 2019

We present observations, which are part of an ongoing investigation, of the CO (J=1–0) emission in the spiral galaxy M51. The spectra were obtained in a beamswitched on-on mode with the Onsala 20 m antenna (beam size ~33″), equipped with a cooled mixer and a 512 ×1 MHz multichannel receiver, and are shown in Figure 1. The inset diagram shows the observed positions superposed on the optical outline of the galaxy. With the present signal-to-noise ratio there is no evidence for an arm-interarm intensity contrast. This is even more apparent in integrated intensity. This result agrees with the lower resolution findings of Rickard et al. (1981). We have observed 13CO in one position (22″ south of the center). The 13CO to 12CO ratio, ∼0.1, agrees with Bell results from observations with a 1:7 beam (Encrenaz et al. 1979).
Optical Features Associated with the Extended HI Envelope of M83
Authors: Wamsteker W. , Lorre J. J. , Schuster H. E.
Published: June 2019

Deep red Schmidt plates (127−04 + RG630) of the galaxy M83 show the presence of extensive faint optical structure well beyond the Holmberg radius of the galaxy. Digital processing has been used to bring these features out in detail. They consist of arc-like structures and clumps of H II regions, which seem to follow the H I distribution and thus are likely to participate in the warping of the H I disk.
Mass Distribution and Dark Halos
Authors: Haud U. , Einasto J.
Published: June 2019

One of the most controversial astronomical paradoxes seems to be the mass paradox : the mass of large astronomical systems depends on the mass determination method. This paradox can be explained by supposing the existence of huge invisible coronas of unknown origin around galaxies. In the present paper we discuss basic empirical evidence of hidden matter in galaxies and examine the total mass distribution.
NGC 3992 – A Galaxy without a Massive Halo
Authors: Gottesman S. T. , Hunter J. H. , Ball J. R.
Published: June 2019

As a continuation of our earlier work (Gottesman and Hunter, 1982), we have reobserved the HI emission from the galaxy NGC 3992. We have combined all the data and produced new maps, at a significantly improved signal-to-noise ratio, of the gas density and velocity distribution with resolutions of ~ 22″ and 25 km s−1. The resultant, angle averaged, HI rotational velocity is shown in Figure 1 for the symmetric and nearly circular flows for r ≤ 3.35′ from the center (r ≤ 14.0 kpc, assuming de Vaucouleurs' (1979) distance of 14.2 mpc for NGC 3992). Shown, also, in Figure 1 is a fit to the observations provided by a Toomre disk of index n = o. No attempt was made to fit the observational data within 1′, in view of the low signal to noise.
HI Observations of the Interacting Galaxies - VV 371 and VV 329
Authors: Grayzeck Edwin J.
Published: June 2019

Recent evidence for the tidal interaction among neighboring galaxies in the form of HI bridges and streamers has been accumulated by Haynes (1981). The successful application of computer simulations to model these encounters has largely been restricted to the nearby systems such as the Milky Way. In this paper, I will report on preliminary observations of the HI distributions associated with two interacting systems - VV 371 and VV 329.
Selfpropagating Stochastic Star Formation and Spiral Structure
Authors: Feitzinger J. V. , Seiden P. E.
Published: June 2019

Spiral structure in galaxies can arise from both dynamic and non dynamic phenomena: spiral density waves and stochastic selfpropagating star formation. The relative importance of these effects is still not known. Deficiences of the original selfpropagating star formation model (where only stars are taken into account) are overcome by explicitly considering the stars embedded in and interacting with a two-component gas (Seiden and Gerola, 1979; Seiden, Schulman and Feitzinger, 1982; Seiden and Gerola, 1982). The two-component gas is essential because it is the means by which we get feedback in the interaction between stars and gas. The coupling between stars and gas regulates and stabilizes star formation in a galaxy. Under proper conditions this model can give good grand design spirals (Fig. 1).
Vertical Structure of Spiral Shocks in a Corrugated Galactic Disc
Authors: Nelson A. H. , Matsuda T. , Johns T.
Published: June 2019

Numerical calculations of spiral shocks in the gas discs of galaxies (1,2,3) usually assume that the disc is flat, i.e. the gas motion is purely horizontal. However there is abundant evidence that the discs of galaxies are warped and corrugated (4,5,6) and it is therefore of interest to consider the effect of the consequent vertical motion on the structure of spiral shocks. If one uses the tightly wound spiral approximation to calculate the gas flow in a vertical cut around a circular orbit (i.e the ⊝ -z plane, see Nelson & Matsuda (7) for details), then for a gas disc with Gaussian density profile in the z-direction and initially zero vertical velocity a doubly periodic spiral potential modulation produces the steady shock structure shown in Fig. 1. The shock structure is independent of z, and only a very small vertical motion appears with anti-symmetry about the mid-plane.
Attacking the Problem of a Selfconsistent Bar
Authors: Petrou Maria
Published: June 2019

One way of approaching the problem of a selfconsistent bar, is to examine the orbits of the stars which make up the bar. Given that there are 1010 such stars and therefore 1010 such orbits, one has to devise a way of studying and classifying them. Once one knows the most important types of orbits which appear in a system and when they appear, can proceed in constructing a selfconsistent bar.