bluuebunny/crossref_metadata_2025 huggingface dataset:
46. Teaching of Astronomy
Authors: Wentzel D. G. , Houziaux L. , Rigutti M. , Buscombe W. , Iwaniszewska C. , Kleczek J. , Kononovich E. V. , Mavridis L. , Okoye S. E. , Peery B. F. , Ringuelet A.
Published: July 2016

The projects of this Commission are increasingly aimed at the astronomically developing countries. The projects are:

International Schools for Young Astronomers. These are the highest-priority activity of the Commission. They last three weeks, have typically 25 to 35 participants, cover a range of astronomical topics with emphasis on practical training, and are funded by the IAU, UNESCO, and local sources. This report covers three schools: i) La Laguna, Tenerife, Spain, September 1979, participants from Spain, Portugal, Canary Islands and five Latin American countries, ii) Hvar, SR Croatia, Yugoslavia, September – October 1980, participants from Balkan and Mediterranean countries, iii) Helwan Observatory, Cairo, Egypt, participants from Egypt, Saudi Arabia, Sudan, Nigeria, Tanzania, Greece, Portugal, Hungary, China.
47. Cosmology
Authors: Longair M. S.
Published: July 2016

A major procedural advance in the determination of the H0 and Ω has been that the problem is now being attacked from many different points of view and to some extent the observations are converging on preferred values of H0 and Ω (Ω = density parameter = 8πGρ0/3H0 where ρ0 is the mean density of matter in the Universe and H0 is the Hubble constant; Ω = 2q0 where q0 is the deceleration parameter). The classical approaches through the redshift-magnitude relation for the most massive galaxies in clusters suggest a value of H0 = 60 km s-1 Mpc (see the review by Tammann in IAU Symp. 63).
Commission 12: Radiation and Structure of the Solar Atmosphere
Authors: Noyes R. W. , Kuperus M. , Uchida Y. , Biao Chen , Deubner F. , Fossat E. , Harvey J. , Kotov V. A. , Leibacher J. , Sivaraman K. R. , Stenflo J. O. , Wilson P.
Published: July 2016

The scope of Commission 12 has broadened somewhat in recent years, to include not only the structure of the solar atmosphere, but that of the solar interior as well. The scientific purview of this commission, and of the present report, are complementary to those of Commission 10 (solar activity). Rather than attempting to review all progress in solar structure studies over the past triennium, this report deals with six topics of great current interest, in which there is a great deal of current work.
V. Dynamics of the Chromosphere and Transition Region
Authors: Grant Athay R.
Published: July 2016

One of the more interesting aspects of the chromosphere-corona transition region is its tendency to exhibit large Doppler shifts. Both the non-thermal velocity component of line widths and the velocity displacement of line positions tend to maximize at temperatures near 105 K. The increase in velocity amplitudes with increasing temperatures below 105 K is readily understood in terms of the increasing sound speed and decreasing densities associated with the outwardly increasing temperature. Why the observed velocity amplitudes should decrease at still higher temperatures is not at all clear, however, and it seems very likely that this phenomenon is indicative of fundamental differences in the dynamics of the upper transition region and corona from those in the lower transition region and chromosphere.
Working Group 4: Structure of Atomic Spectra
Authors: Martin W. C.
Published: July 2016

A Bibliography on Atomic Energy Levels and Spectra covering the period July 1979 through December 1983 is scheduled for publication in late 1984(1). The references in Table 1 are thus limited to papers published or known to be in press in 1984; the selection was made from references giving data on energy levels, wavelengths, and line classifications for spectra of the elements Z < 30. S. Johansson notes that the spectra under investigation in the Physics Department of Lund University, Sweden, include S III, IV, VII, VIII, IX; CI VI, VII, VIII, X; Sc V; the (Ne I) isoelectronic spectra Sc XII-Fe XVII; Ti I; Cr I, II, V; Fe II, III; and several high-ionization spectra of Ni, the work on Fe III and the Ni spectra being done in collaboration with researchers in the Zeeman Laboratory, Amsterdam. Term analyses in progress at the Lund Institute of Technology, as reported by W. Persson, include Ne III and K II, III. This group has recently completed analyses for Kr IV, Rb V, Sr V, VI and has papers in preparation for Rb IV, Y VI, and Xe II. Fourier-transform spectrometric observations at the National Solar Observatory (Kitt Peak) by J. Brault and collaborators are yielding more accurate and complete line lists for the first and second spectra of several elements, including Mg, Al, Ti, V, Cr, Fe, and Ni. Ongoing extensions of the term analyses for some of these spectra were mentioned above; similar work is underway for Mg I, II, Al I, II, and V I, II (E. Biemont, University of Liege) and for Fe I (R. C. M. Learner, Imperial College, London). B. C. Fawcett’s current research at the Rutherford Appleton Laboratory, Oxfordshire, England, includes work on the oxygen-like spectra P VIII through Fe XIX.
Commission 25. Stellar Photometry and Polarimetry
Authors: Tinbergen J , Rufener F. G. , Bessell M. S. , Chugajnov P. F. , Dachs J. , Edwards P. , Glass I. S. , Graham J. A. , Hauck B. , Kilkenny D. , Landolt A. U. , McLean I. S. , Piirola V. , Shakhovskoj N. M.
Published: July 2016

This triennium has in general not been one of spectacular new developments in photometric of polarimetric techniques; rather, existing techniques have been improved and are being exploited by more observatories than before. For this reason, the previous report (31.113.097) should be consulted for a broad survey of the subject, while the present has the character of a progress report.
5. Atmospheres of Accretion Discs
Authors: Pringle James E.
Published: July 2016

Accretion discs are a popular ingredient among theorists for modelling a number of high energy astronomical objects like quasars, active galactic nuclei (Rees 1984) and galactic X-ray sources (Levin and van der Heuvel 1983). However, the observational evidence (as opposed to the strong theoretical presumption) that accretion discs exist in these objects is weak, and in only one case has some attempt been made to argue the case for a disc on the basis of its spectral properties (Malkan 1983). Indeed the structure of accretion discs is sufficiently ill-understood that any progress in this area must rest on a strong interaction between theoretical modelling and the actual observation of accretion discs in action.
47. Cosmology
Authors: Audouze J. , Setti G. , Gunn J. , Hayakawa S. , Longair M. S. , Novikov I. , Tammann G. A. , Trimble V. , de Vaucouleurs G.
Published: July 2016

The preparation of a report dealing with such a large domain is almost an impossible task. Because so many different questions, problems and expertises are assembled under the word “Cosmology”, my approach has been the following: first to divide this field in a somewhat arbitrary fashion into the following sections: very early universe – elementary particle and cosmology – early nucleosynthesiscosmological parameters (Hubble constant, deceleration parameter, cosmological constant) – large scale structures, intergalactic gas, missing mass – clusters of galaxies and intercluster gas – anisotropy of the black body radiation – formation of galaxies – quasars and their evolution – cosmological evolution of radiosources. I have then asked to the most knowledgeable specialists to review briefly each of these most important questions on which many excitinq and very new results have been obtained not only by the astrophysicists themselves but also by particle physicists, nuclear physicists, theoretical physicists, … This is why the reader will read in section 1 the report on primordial nucleosynthesis written by G. Steigman, in section 2 Anisotropy of the black body radiation by D.T. Wilkinson and E. Meichiorri, in section 3 Clusters of galaxies by 3. Einasto, in section 4 Galaxy formation by B.J.T. Jones, in section 5 Quasars and their evolution by M. Schmidt and in section 6 the Cosmological evolution of radio sources by R.A. Windhorst. Let me thank these colleagues for their excellent work in writing these various reviews.
48. High Energy Astrophysics
Authors: Giacconi Riccardo , Cesarsky Catherine , Clark G. , Pacini F. , Scheuer P. A. G. , Salpeter E. E. , Sunzaev R. A. , Truemper J. , Woltjer L. , Qu Q.
Published: July 2016

In view of the broad range of topics covered by Commission 48 and the consequent inevitable overlap with other commissions, it is not feasible to produce a comprehensive self-contained report. The commission therefore restricts its report to a selected list of accessible recent review articles and conference reports, where up-to-date summaries of various topics can be found. Such a list is given below.
Working Group for Planetary System Nomenclature (Committee Of The Executive)
Authors: Masursky H. , Aksnes K. , Hunt G. E. , Marov M. Ya. , Millman P. M. , Morrison D. , Owen T. C. , Shevchenko V. V. , Smith B. A. , Tejfel V. G. , Boyce J. M. , Burba G. E. , Komkov A. M. , Rosenthal J. D.
Published: July 2016

Since the last General Assembly in Patras, Greece, we have held three meetings of the Working Group. The 10th Meeting was held in Mzkheta, the ancient capital of Georgia, USSR, hosted by their Academy of Sciences on April 3-7, 1984. All members except one, who was represented by a member of his Task Group, were present at the very productive meeting.
III. Active Regions
Authors: Falciani R.
Published: July 2016

During the past three years arguments related to the AR physics can be found in the proceedings of the following meetings: Chromospheric Diagnostics and Modelling, NSO Sacramento Peak, 1984 (I); The Hydromagnetics of the Sun, Noordwijkerout, ESA, 1984 (II); Solar and Stellar Physics, Titisee, 1987 (III). Many aspects concerning the high activity levels of AR’s can also be found in the proceedings of large number of meetings organized on solar flares. Microwave mapping is reported in Section VII. Some results are also reported in Section II.
IV. Prominences and Filaments
Authors: Malherbe J.M.
Published: July 2016

This report is a summary of the work done on the physics of prominences and filaments. An overview of modern observations has been written by Hirayama (1985). The behaviour of solar Coronal and Prominence Plasmas (CPP) has been the topic of two SMM meetings, organized by A. Poland in 1985 and 1986, in Goddard Space Flight Center. An extensive review of the subject (formation, spectroscopic diagnostics and instabilities, with a large amount of contributed papers) can be found in the proceedings (Poland, 1986 (I)). Also, the physics and the structure of prominences will be discussed, from a more theoretical point of view, during a next workshop, in Palma de Mallorca, organized by E. Priest and J.L. Ballester in November 1987.
2. X-Ray Astronomy
Authors: Pounds K.A.
Published: July 2016

X-ray astronomy has continued to flourish in the three years covered by the present report (to June 1987) despite the continuing scarcity of new missions. The European EXOSAT has probably made the greatest impact during this period, carrying out over 2000 separate observations up to it’s loss of attitude control in April 1986. A major reason for the success of EXOSAT was the unusual spacecraft orbit which provided uniquely long source exposures, uninterrupted by Earth occultation, of up to 70 hours duration. The continuous light curves of many galactic and extragalactic sources have proved particularly valuable in studying details of time variability over a broad frequency range and in this respect the EXOSAT data archive is unlikely to be superceded in this century. For several months after the demise of EXOSAT, astronomers had no operational X-ray satellite for the first time since the launch of Uhuru in 1970. This unfortunate state of affairs ended in February 1987 with the successful launch of the Japanese ASTRO-C satellite. Three months later, observations began with several X-ray instruments on board the Soviet MIR space station and at the time of writing both GINGA (the post-launch name of ASTRO-C) and the MIR instruments are working well.
4. Infrared Space Astronomy
Authors: Herter Terry
Published: July 2016

The period from 1984 through 1987 saw no new infrared space missions. Investigations, however, continued with airborne, balloon, and rocket activities, and follow-up analysis of data from the Infrared Astronomical Satellite (IRAS). Two major ephemeral events occurred during this time, the Comet Halley apparition and SN 1987a, the supernova in the Large Magellanic Cloud. With improved analysis on the database and follow-up observations new results have been forthcoming from IRAS. This work may help astronomers understand everything from the origin and evolution of quasars to the composition of material in cometary nuclei.
Working Group for Planetary System Nomenclature

: (Committee of the Executive Committee)
Authors: Masursky H. , Aksnes K. , Hunt G.E. , Marov M. Ya. , Millman P.M. , Morrison D. , Owen T.C. , Shevchenko V.V. , Smith B.A. , Tejfel V.G. , Boyce J.M. , Burba G.E. , Komkov A.M. , Rosendhal J.D.
Published: July 2016

Since the General Assembly at New Delhi in November 1985, the Working Group held two meetings within six weeks of each other; most members of the Working Group and several members of Task Groups were able to attend at least one of these meetings. The thirteenth meeting of the Working Group was held at Toulouse, France on June 30 to July 2,1986; the fourteenth meeting was held at Moscow, USSR, on August 10,1986; the fifteenth meeting took place from August 13 to 15 in Soviet Armenia.
Division X: Radio Astronomy
Authors: Moran James M.
Published: July 2016

Division X provides a common theme for astronomers using radio techniques to study a vast range of phenomena in the Universe, from exploring the Earth’s ionosphere or making radar measurements in the solar system, via mapping the distribution of gas and molecules in our own and other galaxies, to the study of previous vast explosive processes in radio galaxies and QSOs and the faint afterglow of the Big Bang itself.
Commission 26 : Double and Multiple Stars
Authors: McAlister H.A.
Published: July 2016

The observational study of double and multiple stars is traditionally seen as comprised of several specialized subfields, each defined by particular observational selection effects. Improvements in increased precision and accuracy, higher resolution, higher signal-to-noise ratios, greater sensitivity etc.), are leading the study of double stars to a truly coherent field. Significant advances in ground-based spectroscopy and interferometry provide a framework from which we can prepare for the future. The contributions to be made from space are currently in a state of uncertainty as we await results from the Hubble Space Telescope and Hipparcos.
17. The Moon
Authors: Anders E.
Published: July 2016

Members of Commissions 16 and 17 have voted by a substantial margin (102 yes, 4 no, 1 abstention) to merge the two Commissions. The merger will take effect at the 17th General Assembly.
19. Rotation of the Earth
Authors: Vicente R. O. , Yumi S.
Published: July 2016

The commission deeply regrets the deaths of our colleagues which were reported in the several circular letters issued during the last three years.
20. Positions and Motions of Minor Planets, Comets and Satellites
Authors: Marsden B. G.
Published: July 2016

The past triennium has been noteworthy for several significant discoveries in the outer part of the solar system. The discovery of the rings of Uranus was inspired by the activities of Commission 20’s new Working Group on Occultations. Although the discovery of a probable Plutonian satellite has not yet been completely confirmed, the implication that Pluto’s mass is only 0.002 earth masses may make it desirable to consider whether Pluto should be relegated to minor-planet status. The orbit of Pluto is in fact not greatly dissimilar to that of the object classified as the new minor planet (2060) Chiron, which was found to have its aphelion near the orbit of Uranus and its perihelion just inside the orbit of Saturn.
49. The Interplanetary Plasma and the Heliosphere
Authors: Hewish A.
Published: July 2016

It is now generally recognized that the solar wind represents that part of the solar corona which is not confined by the solar magnetic field, and therefore escapes into interplanetary space. The escaping gas is heated by sources of solar origin (presumably low frequency waves) to about 2 x 106 K within a distance less than (1/20) R from the sun’s surface; although the solar wind temperature decreases thereafter, heating sources may continue to act through 1 a.u. heliocentric distance. A transition from subsonic to supersonic flow occurs within a few solar radii of the sun’s surface, heat conduction representing the principal energy supply for the acceleration of the solar wind. However, additional accelerating processes may also be active.
Encouraging the International Development of Antarctic Astronomy
Authors: Burton M.G.
Published: July 2016

The Antarctic plateau provides the best site conditions on the Earth for a wide range of astronomical observations, both of photons and particles. This is a result of the unique combination of cold, dry and tenuous air found only there. Wintertime temperatures average below -60˚C, with minimal diurnal variation, the precipitable water vapour content is below 250 μm, the katabatic wind is low on top of the plateau and there are no jet streams at high altitude. The vast quantities of pure ice can be used as an absorber for particle detectors. Secondary benefits include continuous viewing for any source visible, lack of pollution and dust in the atmosphere, and low electromagnetic interference. Considerable activity is now focussed at the South Pole on developing facilities for astronomy. Initial investigations of higher sites have begun, particularly at Dome C.
6. Commission Des Telegrammes Astronomiques
Authors: Jones H. Spencer , Hansen Julie M. Vinter
Published: July 2016

The Bureau suffered a sad loss, through the death on April 5, 1947, of its director Prof. Elis Strömgren who had conducted its work with never failing enthusiasm and with great efficiency since 1922. In June 1947 the supervision of the Bureau was entrusted to the writer. The following report may not be altogether complete owing to my absence, for 6 years, in the U.S.A., when I was out of touch with the activities of the Bureau. The last report by Prof. E. Strömgren was dated February 26, 1938; for the rest of the year very few data have been found, hence my report will cover the period January 1, 1939 to December 1, 1947.
12. Commission De La Radiation Solaire Et De La Spectroscopie Solaire
Authors: Abetti M. G.
Published: July 2016

The report is compiled from information supplied by several members, in response to a request for information. Several members replied that they are not now actively concerned with the subjects with which this Commission is dealing. No attempt has been made to review the work done in these subjects in the years since the last General Assembly of 1938.

Daily determinations of the solar constant have been continued by the staff of the Astrophysical Observatory of the Smithsonian Institution at Montezuma (Chile) and at Table Mountain (U.S.). Apparatus and methods are being developed by Abbot and his co-operators for the daily measurement of atmospheric ozone and of its band of absorption, 9–10 μ.
19. Commission De La Variation Des Latitudes
Authors: Jones Harold Spencer
Published: July 2016

When, in May 1922 after the First World War, the I.A.U. and the I.G.G.U. met for the first time it was decided that the systematic study of the motion of the pole should be continued. This study had been commenced over 23 years earlier by the International Geodetical Association and had been continued without interruption during the war, thanks to the keenness of the observers and the work of the Swiss and Dutch geodesists and astronomers, who had undertaken to maintain the necessary contacts between the observing stations and the Potsdam Central Office. The Second World War, which broke out barely two decades later, had more serious consequences for this study. The generous and worthy offer of our Swiss colleagues to be intermediaries between the belligerent countries and to help in the exchange of data between the observing stations and the Central Bureau passed unheeded. The Italian Foreign Minister at the time refused to allow the observing books to be transmitted. We had hoped that, when hostilities were over and communications had been re-established, we should be able to obtain, although late, the complete series of observations.
31. Commission De L’Heure
Authors: Nørlund M. N. E.
Published: July 2016

La sixième Assemblée Générale de l’Union Astronomique Internationale adopta, d’après la proposition de la Commission de l’Heure, la résolution suivante:

La Commission approuve la proposition britannique transmise par le Comité exécutif de l’U.A.I. d’adopter à partir du 1er janvier 1940 les positions d’étoiles du système FK3 pour les déterminations d’heure et leur utilisation en vue de l’émission des signaux horaires.
32. Commission Des ‘Selected Areas’
Authors: van Rhijn M. P. J.
Published: July 2016

The following lines give a summary of the work of Kapteyn’s Plan of Selected Areas from January 1938 up to September 1947.
36. Commission De La Spectrophotometrie
Authors: Minnaert M. M. G. J.
Published: July 2016

By publishing at each meeting a report on the progress of astronomical spectrophotometry, our Commission has done in the past work which has been appreciated. Such a report may be expected to be of special usefulness in the present circumstances, after the disruption of normal communications for so many years. For this purpose, an attempt has been made to give a list of the most important publications, as a bibliographical appendix to this report. The titles are quoted in abridged form. My thanks are due to many members of the Commission, who contributed materially to this list and helped me with important information. I apologize for omissions, nearly inevitable in this post-war period. In future some restriction of the field of our activity ought to be considered; spectrophotometry is nowadays so general an astrophysical method, that it is nearly impossible to give a more or less complete survey of its applications to all different fields of our science. This report was finished on January 1, 1948. A few recent publications have been included in the bibliographical list.
37. Commission Des Amas Stellaires
Authors: Shapley M. H.
Published: July 2016

Unlike the investigations in many fields of astronomy, the work on star clusters offers few problems for practical international or inter-observatory co-operation. But there are two useful projects that the International Commission can undertake: the reporting of the researches in progress at the various observatories, and the co-operative listing of useful categories of research on star clusters. The list may serve as a guide for new workers in the field. Also there is, of course, much value in the mutual discussion of researches. Such interchange of ideas may be the most useful outcome of the Commission’s conferences at the Zürich meeting of the International Astronomical Union.
2. Solar Abundances of the H, C, N and O Atoms Deduced from Molecular Abundances
Authors: Hunaerts J.
Published: July 2016

A priori it would seem possible to determine the solar abundances of the H, C, N and O atoms on the basis of the solar abundances of the CN, CH, C2, NH and OH molecules. Such a determination entails two distinct problems:

(1)

The determination of the molecular abundances with the help of the measured intensities of individual rotational lines.

(2)

The calculation of atomic abundances on the basis of the equations of dissociation equilibrium.
31. Commission de l’Heure
Authors: Nörlund M. N. E. , Banachiewicz MM. , Bianchi  , Camera  , Castro  , Curry  , Deslandres  , Dyson  , Esclangon  , Gallo  , Lambert A. , Lejay  , Littell  , Mašek  , Moreau  , Ribeiro  , Sampson  , Silva  , Sollenberger  , Sôtome  , Stewart  , Voûte
Published: July 2016

Sur la proposition du Comité exécutif, l’Assemblée générale du 13 juillet 1928, réunie à Leyde, adopta la résolution suivante:

“Le Comité exécutif espère que d’ici à la fin de la présente convention (31 décembre 1931) la direction du Bureau de l’Heure pourra être exercée par le Directeur de l’Observatoire de Paris, et qu’après cette date l’activité actuelle du Bureau pourra être conservée sans faire appel aux fonds limités de l’Union, peut-être avec la coopération d’observatoires et autres institutions.”
35. Commission de la Constitution des Étoiles
Authors: Eddington Arthur , Emden MM. , Fowler R. H. , Jeans  , Milne  , Pannekoek  , Rosseland  , Russell  , Vogt  , Woltjer
Published: July 2016

This Commission deals with a subject in which there is Uttle scope for organizing activity. The organization of the observations, which provide the data used in research on the constitution of the stars, is assigned to other Commissions. Theoretical investigations are a matter for individual effort, and cannot be organized by a Committee except in special cases where they involve long computations of routine character.
Commission 8. (Meridian Astronomy.)
Authors: Dyson Frank , Oort J. H.
Published: July 2016

In connection with the plans of the Pulkovo Observatory for removing one of their vertical circles to the southern hemisphere the following recommendation was proposed by Dr Morgan and seconded by Prof. Boss:

“The Commission regards the proposal of the Pulkovo Observatory to establish the Vertical Circle in as nearly equal a southern latitude as possible with great sympathy. We believe this will be of very great value in the improvement of fundamental decimations.”

Dr Lundmark read a report on the programmes for the Lund meridian circle, which programmes include stars of special interest, such as long- and short-period variables, extremely red non-variable stars, B-emission stars, moving clusters, nebulous stars, nuclei of planetary nebulae and of anagalactic objects, etc. The definite programme will contain at least 3000 stars, results for some 400 of which have already been obtained. It is planned to extend the observations to stars in the southern hemisphere as soon as financial conditions will permit the erection of a southern station.
Commission 14. (Wave-Lengths.)
Authors: Babcock H. D. , Meggers W. F.
Published: July 2016

A provisional list of recommendations based upon the Draft Report prepared by Prof. Fowler served as a guide for discussion and action by the committee. The recommendations, together with a digest of the discussion and the action taken, are reported below as a record of the proceedings of Commission 14.

1. It is recommended that two or more observers should investigate the possibility of simplifying the specification for the production of the primary standard by using a source that will give well-defined fringes with retardations greater than 200,000 wave-lengths. No action taken.
6. Commission des Télégrammes Astronomiques
Authors: Strömgren M. E. , Dawson MM. , Jackson J. , Jones Spencer , Shapley  , Wood
Published: July 2016

From June 4,1932 (date of the last report) up to the present date the Bureau has distributed 452 telegrams and published 153 circulars (Nos. 382-534).

Again the Bureau has been supported by a great many colleagues and institutions.

As heretofore, the leading principle in our work has been as far as possible to procure provisional data for the continuous observation of new objects. Following this line the telegraphic service has been used when necessary to safeguard new discoveries, while in all cases possible the circulars have been depended on. Thus, as before, in dubious cases we have, to begin with, sent a telegram to a few correspondents only, asking for control. In cases of rediscovery of periodic comets and in other cases, when there was no risk of losing the object, we have distributed the announcement through the circulars.
28. Commission des Nébuleuses et des Amas Stellaires
Authors: Shapley M. , Baade MM. , Bernheimer  , Carpenter  , Hogg  , Hubble  , Humason  , Jeans  , Lampland  , Lemaître  , Lundmark  , Madwar  , Paraskévopoulos  , Parvulesco  , Reinmuth  , Reynolds  , Roberts Mme , Slipher MM. V. M. , Trumpler  , Vanderlinden  , Van Maanen  , Von Zeipel  , Wirtz  , Wright W. H.
Published: July 2016

1. Since the field covered by Commission No. 28 extends over the problems of three very different types of objects—external galaxies, galactic nebulae, and star clusters—it has been proposed occasionally that the Commission might well be subdivided, or possibly eventually split into three separate Commissions. As Trumpler points out, these three fields “have often been grouped together...more on a historical basis than on an actual similarity of the researches... which are more and more drifting apart.” But some members of the Commission have noted that a distinct difference also separates globular clusters and galactic clusters; and that planetary nebulae and dark absorbing clouds involve at times widely different types of investigations. The chairman of the Commission has made a canvass of the opinions of the members and finds that a large majority believe that no division or subdivision is advisable at this time. It is suggested that the organization or reorganization of a Commission should be left to the Union as a whole or to the Executive Committee.
36. Commission de la Spectrophotométrie
Authors: Plaskett M. H. H. , Baillaud MM. J. , Beals  , Davidson C. R. , Dufay  , Dunham  , Eddington  , Elvey  , Fabry  , Greaves  , Hogg  , Kienle  , Lindblad  , Menzel  , Milne  , Minnaert  , Öhman  , Pannekoek  , Gaposchkin Mme Payne , Redman MM. , Rosseland  , Russell  , Sampson  , Struve  , Tiercy  , Unsold  , Woolley
Published: July 2016

The present report is the first for which this newly-formed Commission has been responsible. In view of this fact, and in view of the still exploratory nature of many investigations in spectrophotometry, as well as the need for the highest measure of individuality in the attack of the not simple problems involved, it would be premature to propose, simple though it might be to do so, any far reaching plans for co-operative schemes of investigation. These undoubtedly will play a part in the later work of the Commission, but what appears to be needed now is a closer definition of the aims of spectrophotometry, and at least a reference to the many branches of the subject where investigation is needed. The present report attempts to deal with these topics in three successive sections, concerned in turn with the unique property of spectrophotometric measures, the fields of application of spectrophotometry, and recent developments in a still incomplete and difficult technique.
Commission 8. (Meridian Astronomy.)
Authors: Jackson J. , Hins C. H.
Published: July 2016

Dr Boss stated that he hoped to publish the first two volumes of the General Catalogue by the middle of the next year and the complete catalogue of four volumes by the end of 1936. A 5th volume containing the introduction will be published later.

Dr Jackson reported that Prof. Kopff would postpone the choice of the 3000 fundamental stars for photography till after the publication of Boss’s G.C.

Dr Gerasimoviç reported that the fundamental stars of magnitudes 7m.5—8m.5 which have been selected by Dneprovski for observation at Pulkovo and Nikolayev were stars of the M giant type.
Commission 11. (Chromospheric Phenomena.)
Authors: D’Azambuja M. L. , Newton M. H. W.
Published: July 2016

Le Président évoque la mémoire du Dr C. E. Saint John, décédé peu de temps avant le Congrès et qui, alors qu’il présidait la Commission groupant toutes les recherches de Physique solaire, portait un intérêt très vif aux travaux dont s’occupe maintenant la Commission n.

Deux demandes de subventions ont été soumises à la Commission: l’une, de M. le Prof. G. Abetti, pour continuer la publication des Immagini spettroscopiche del bordo solare; l’autre, de M. E. Esclangon, pour poursuivre celle des Cartes synoptiques de la chromosphère établies à Meudon. Les demandes de subventions sont approuvées par la Commission.
8. Commission de L’Astronomie Méridienne
Authors: Dyson Frank , Jackson M. J. , Armellini MM. , Baillaud R. , Boss  , Camera  , Chandon Mme , Courvoisier MM. , da Gama  , Danjon  , Dneprovsky  , Fayet  , Gyllenberg  , Hins  , Jeffers  , Jones Spencer , Kopff  , Lambert A. , Moreau  , Morgan H. R. , Schorr  , Stewart R. M. , Voronoff  , Zimmer
Published: July 2016

A circular letter was sent out to all members of the Commission in December 1937, to which the majority have replied. While work is going on steadily in the Observatories where meridian observations are carried out, comparatively few catalogues have been published since 1935. In view of the very full report made three years ago it is only necessary to draw attention to the progress which has been made in the interval.
Stellar Evolution
Authors: Schwarzschild M.
Published: July 2016

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.
19. Rotation of the Earth
Authors: Melchior P. , Smith H. M. , Fedorov E. P. , Markowitz W. , Yumi S.
Published: July 2016

La commission déplore le décès de Madame Aksentieva, directeur de l’Observatoire de Poltava et du Professeur Demetrescu, ancien directeur de l’Observatoire de Bucarest.

L’étude de la rotation de la Terre poursuit plusieurs objectifs scientifiques fondamentaux:

(1)

Fournir des données d’observations continues d’où l’on pourra tirer un ensemble de paramètres servant de base à l’élaboration des théories sur la constitution interne de la Terre et sur la dynamique du système Terre-Lune.

(2)

Fournir à tout moment la position d’un trièdre de référence attaché au manteau terrestre par rapport à un trièdre fixé dans l’espace, travail d’une nécessité primordiale pour l’astronomie fondamentale, la géodésie et la navigation spatiale.

(3)

Permettre de nouvelles recherches sur certaines constantes fondamentales de l’astronomie (nutation, aberration) grâce à la constitution de très longues séries d’observations homogènes.
27. Variable Stars
Authors: Detre L. , Eggen O. J. , Bojarčuk A. A. , Herbig G. H. , Kippenhahn R. , Kwee K. , Odgers G.
Published: July 2016

This Report in arrangement of the material follows closely that written by Dr. Herbig for the last IAU General Assembly. It consists of four parts, each written by a different author. The first deals with variable stars in general, and was prepared by the President of Commission 27, with the exception of a section on the Theory of Variable Stars, very kindly written at his request by Prof. Kippenhahn. Appendix I on the Spectra of Variable Stars was prepared by Dr M. W. Feast, Chairman of that Committee of Commission 27. Appendix II covers the Variable Stars in Clusters, written by Dr Helen Sawyer-Hogg, Chairman of that Committee. Appendix III is a Report of the Working Group on Flare Stars, prepared by Drs Andrews, Chugainov, Gershberg and Oskanjan. No report has been received from the Working Group for Nomenclature for Magellanic Cloud Variables. About supernovae see the report of the Committee of Commission 28 for Research on Supernovae. On pulsars see the Reports of Commissions 25 and 40. Our thanks are due to all members of the Commission and to other astronomers occupied in variable star research, who have assisted in collecting the material for this report. Great help was a general report on flare stars by the competent Working Group.
29c. Groupe de Travail Sur Les Étoiles Be
Authors: Herman R.
Published: July 2016

A. Peton (Meudon) à partir de spectres à petite dispersion, a évalué une période de 33 ans pour les variations de l’émission de HD4180, une classe B5 IV et des oscillations assez importantes de l’enveloppe absorbante sur 3–4 ans (non publ.).

F. R. Hickok (Dunlap) a étudié les structures fines et les vitesses radiales de ɸPer à grande dispersion de telle sorte que les courbes de vitesse sont plus détaillées, mais, la période ne change pas. Probablement binaire. Des difficultés sont soulignées (non publ.).

Des variations spectrales et de vitesse radiale ont été observées par M. Hack et P. Stenner (Trieste, dans l’enveloppe de ζTau (publ.) ainsi que par Van der Wel (Utrecht) pour la période 1964-66 (non publ.). A. M. Delplace (Meudon) a mis en évidence une relation très étroite entre les profils Balmer H et la période de 7 ans. L’enveloppe, en moyenne, est en récession (publ.).
33. Structure and Dynamics of the Galactic System
Authors: Contopoulos G. , McCuskey S. W. , Blaauw A. , Bok B. J. , Haradze E. K. , Kerr F. J. , Kuzmin G. G. , Lin C. C. , Schmidt M.
Published: July 2016

The present report is drastically shorter and, therefore, different in form from previous reports. While galactic research has increased considerably in recent years, the financial situation in the IAU made it necessary to reduce the size of the reports to half their previous size. This obliged us to adopt an almost telegraphic style in our report. However, an extended version of the report, including also the necessary references, will be published by the University of Thessaloniki and distributed to members of Commission 33. Any other interested astronomer may write to ask for a copy.

The report has been prepared by G. Contopoulos (Sections I, V, VI) and S. McCuskey (Sections II, III, IV). In our work we have been helped by Drs Kerr (radio astronomy) and Haradze (Russian contributions). Dr Elvius has written the Report of the Committee “Selected Areas”. We could cover the literature up to the fall of 1969, plus work in progress, reported by members of our commission.
44. Astronomical Observations from Outside the Terrestrial Atmosphere
Authors: Wilson R. , Prokof’ev V. K. , Blamont J. E. , de Jager C. , Goldberg L. , Lüst R. , Smith F. G. , Tousey R.
Published: July 2016

In view of the limitation on length set by the cost of producing the IAU Reports, the present report can only be a selection of the most important advances during the past three years and not a complete review of the field.

Attempting to pick out a few points of interest, since the last report improvements have been made in recording solar X-ray spectra and in high spatial resolution imaging; the OSO satellite programme continues to produce valuable data. The eclipse experiments planned for March 1970 will, if successful, provide a considerable amount of new information. The solar iron abundance is still a subject of interest in view of the revision of oscillator strengths used in the photospheric analyses. Further interplanetary observations have shown that the general nature of the solar wind at the Earth does not depend on the phase of the solar activity cycle, and have revealed large increases in the abundance of helium in the solar wind following solar flares.
Commission 14: Atomic and Molecular Data
Authors: Kononov E. Ya.
Published: July 2016

The rapid expansion during the past few years of the spectral region accessible to astronomical observers, from gamma rays to the radio region, has resulted in a corresponding expansion of the need for a wide variety of atomic and molecular data. Included are needs for accurate wavelengths, atomic and molecular energy levels, and transition probabilities. The continually improving resolution that has been attainable has resulted in the requirement of improved insight into line broadening mechanisms of various types. This expansion has placed an increasing premium on data compilation and dissemination, so that available information can be made readily available to potential users. Among the numerous compilations that have appeared might be mentioned the important National Bureau of Standards Bibliography on Atomic Levels and Spectra, which is up-dated periodically via successive supplements, and the NBS compilation and bibliography by the Data Center on Atomic Transition Probabilities. Several compilations or bibliographies on collision cross-sections are now available, such as that published by the Information Center at JILA. In the field of molecular spectra there has appeared the very comprehensive “Constants of Diatomic Molecules” by Huber and Herzberg. Other useful compilations are referred to in the reports of the five Working Groups that appear below.
Commission No. 9: Instruments and Techniques (Instruments et Techniques)
Authors: Humphries C.M. , Davis J.
Published: July 2016

Given here are reports on the scientific and business meetings held in Baltimore involving Commission 9 only. Reports on the following Joint Commission Meetings co-sponsored by Commission 9 (JCM 3 and JCM 6), and on three additional meetings organised jointly with other Commissions, will be found elsewhere in this Volume or in Highlights of Astronomy (Volume 8):

-

High Angular Resolution Imaging from the Ground (JCM 3)

-

Stellar Photometry with Array Detectors (JCM 6)

-

Problems of IR Extinction and Standardization (with Commission 25)

-

Future Space Programs (with Commission 44)

-

Gamma-ray, X-ray, Extreme and Far UV, IR and Radio Astronomy from Space (with Commissions 40 and 44)
Commission 50: Protection and Identification of Existing and Potential Astronomical Observational Sites
Authors: Isobe S.
Published: July 2016

During the past triennium many efforts have been made by individual members and Commission 50 to keep a good observational environment, along the lines set up by the previous Commission 50 president, P. Murdin. The number of commission members is 65, which is unchanged from the previous period. Since our problems become more severe year by year and are connected directly to the activities of all observational astronomers and indirectly to those of all theoreticians, the commission should have made an effort to increase the number of active members.

The book “Adverse Environmental Impact on Astronomy” edited by D. McNally was published by Cambridge University Press in 1994. This book is a direct output of a meeting held by UNESCO, ICSU and IAU at the headquarters of UNESCO in Paris from June 30 to July 2 in 1992, and shows nearly all the problems which we are facing.
11 . Absorption of radio waves in the ionosphere and distribution of electron concentration in the F2layer
Authors: Kazantsev A. N.
Published: July 2016

One of the methods used in the treatment of the results obtained during radio observations of Earth satellites consists of determining the radio-wave absorption coefficients by measurements of the electric-field strength at comparable positions.

Over the territory of the Soviet Union the Earth satellites sometimes passed below the maximum of the .F2-layer, sometimes above it, and sometimes near it.
The Accuracy of Ground-Based Optical Interferometry Observations
Authors: Hutter Donald J.
Published: July 2016

The problem of wide-angle astrometry via interferometry is to recover the two coordinates for each star from the observed delays. In the absence of atmospheric turbulence, the geometrical delay can be defined as: dG, ij(t) ≡ dj(t) ‒ di(t) = Bij(t)·ŝ0 ‒ Cij. Here the geometrical delay is the difference between the delay line lengths di and dj that is required to equalize the effective optical paths from the star to the point of beam combination via each of two apertures i and j. Bij(t) is the baseline between the apertures, ŝ0 is the star position, and Cij is the difference between the ‘fixed’ internal optical path lengths Ci and Cj within the instrument. In principle, sufficient delay measurements would allow solution for the baseline vectors and the delay constants, as well as the positions of the stars. However, the actual situation is greatly complicated by the presence of the atmosphere and the fact that neither the delay ‘constants’ Cij nor the baseline vectors are stable over time. The design of, and the analysis of the data from, any ground-based optical interferometer must overcome all three of these effects. The design, operation, and the analysis of data from the Navy Prototype Optical Interferometer (NPOI) are presented here as examples of how to overcome the effects of the atmosphere and the instrumental instabilities in order to achieve accurate wide-angle astrometry. The status of the implementation of these techniques at the NPOI is presented.
Relativity in Modern Astrometry and Celestial Mechanics — An Overview
Authors: Klioner S.
Published: July 2016

After a short introduction into experimental foundations of general relativity, an overview of modern relativistic modelling of astronomical observations is given. The principal relativistic effects in various kind of observations are reviewed, and the problems for increasing accuracy of the astrometric catalogs due to general relativity are formulated.
Possible Relativistic Definitions of Parallax, Proper Motion and Radial Velocity
Authors: Klioner S.
Published: July 2016

It is argued that the relativistic definitions of parallax, proper motion and radial velocity consistent with an accuracy of 1 μas should be considered only within a well-defined algorithm of relativistic reduction of observational data. Such an algorithm is formulated and the corresponding definitions of astrometric parameters are discussed.
Relativistic Models for a GAIA-Like Astrometry Mission
Authors: de Felice F. , Vecchiato A. , Bucciarelli B. , Lattanzi M.G. , Crosta M.
Published: July 2016

A non-perturbative general relativistic approach to global astrometry was developed by de Felice et al. (1998) to handle satellite astrometry data in a genuine relativistic framework. In this contribution, the framework above has been further exploited to account for stellar motions and parallax. Because of the relevance that accurate knowledge (to 10−5 or better) of the relativistic parameter γ has to fundamental physics, a Parametrized Post-Newtonian (PPN) model has also been implemented, which allows the direct estimation of γ along with the astrometric parameters. These models have been tested on end-to-end simulations of the mission GAIA. The results show that, within the limitation of the simulation and the assumptions of the adopted model, measurements accurate to 100 μarcsec of large arcs among stars repeated over a few years can be modelled to establish a dense reference frame with a precision of a few tens of μarcseconds. Moreover, our experiments indicate that γ can be estimated to better than 10−6.
Crossing the “Yellow Void” – Spatially Resolved Spectroscopy of the Post–Red Supergiant IRC+10420
Authors: Humphreys Roberta M. , Davidson Kris , Smith Nathan
Published: July 2016

IRC+10420 is a post–red supergiant at the empirical luminosity boundary in the HR diagram. It has now reached a stage in its blueward evolution where increasing opacity and partial ionization destabilize its atmosphere leading to rapid mass loss. Indeed, its wind is so dense that it is opaque and hides the underlying star. We have obtained HST/STIS spectroscopy with spatial resolution good enough to separate the star from its complex ejecta with numerous arcs, knots and jet-like features. The ejecta form essentially a reflection nebula, allowing us to view the star from a range of directions. The kinematics of the ejecta cannot be reconciled with existing models with either an equatorial disk or a bipolar outflow. Therefore we propose a model with a uniform spherically symmetric outflow of gas with random, asymmetric ejections superimposed. In our model, local instabilities allow for inflowing and outflowing material to coexist.