bluuebunny/crossref_metadata_2025 huggingface dataset:
76. Location on Jupiter of a source of radio noise
Authors: Shain C. A.
Published: July 2016

A search of old records of cosmic noise, taken in the Radiophysics Laboratory at 18·3 Mc./s., has confirmed the discovery, by Burke and Franklin [1], of radio radiation from Jupiter, and has further shown that in 1951 the radio radiation came from a very localized region of the planet.
78. The lunar occultation of a radio star and the derivation of an upper limit for the density of the lunar atmosphere
Authors: Elsmore B.
Published: July 2016

Observations were made at Cambridge on 26 April 1955 of the lunar occultation of the large-diameter radio source in the constellation of Gemini. This radio source, having r.a. 06h 13m 37s and dec. 22° 38′ (1950·0), has been identified by Baldwin and Dewhirst (1954) [1] as the galactic nebulosity IC443, which consists of a filamentary structure contained within a circular region of 24′·5 radius. Baldwin and Dewhirst also succeeded in measuring the distribution of radio ‘brightness’ across the source using an interferometric method; their measurements indicate that the diameter of the radio source is approximately the same as that of the visible nebulosity.
Radio astronomy and the solar system
Authors: Smith F. G.
Published: July 2016

Radio astronomy has been expanding into outer space so fast in recent years that it is pleasant to find our own solar system at last receiving the attention it deserves. In this session we are concerned with everything within the system except the sun and our own planet. I start with a question, to which I shall return later: Where does the sun end? In another session you will hear of the experiments on the far-out parts of the solar corona; here we are concerned with interplanetary space as well as with the planets themselves, and what lies within this region may or may not be considered part of the solar corona.
The rapid fading of moon echoes at 100 Mc/s
Authors: Evans J. V. , Evans S. , Thomson J. H.
Published: July 2016

In recent years the way in which the moon reflects radio waves has been the subject of much study. Observations by Yaplee [1] at 2860 Mc/s, Trexler [2] at 198 Mc/s, Evans [3] at 120 Mc/s, and others show that radio waves are reflected principally by a small region at the center of the moon's visible disk which has a radius of the order of one-third of the lunar radius.
On the regions over sunspots as studied by polarization observations on centimeter wavelengths
Authors: Gelfreich G. , Korol'Kov D. , Rishkov N. , Soboleva N.
Published: July 2016

The observations of the sun at centimeter wavelengths made at Pulkovo in 1956–58 have shown: (1) There are regions of appreciable size over the majority of sunspots that have “enhanced” radio emission at centimeter wavelengths [1]. The nature of this emission shows that it belongs to the slowly varying component. In fact, as long as a group of sunspots persists, the flux of such an active region preserves its almost constant value. (2) The emission is partly circular, the polarized flux changing in magnitude but inappreciably. The sign of polarization rotation remains constant [2], which appears to be positive proof that a rather intense and stable magnetic field exists in these regions. (3) The extent of the regions is about that of the spot nuclei [3]. (4) Their brightness temperature amounts to several million degrees. (5) The height at which enhanced radio emission is produced is of the order 1.07 ± 0.02R⊙ [4].
Solar emission at 10-cm wavelength
Authors: Covington A. E.
Published: July 2016

The significance of 10-cm radio observations for studying the physical conditions in the lower corona of the solar atmosphere and for providing an index of solar activity comparable with the Zürich sunspot number is now well established. This radio emission from the solar disk has been observed daily at the Laboratories of the National Research Council of Canada in Ottawa since 1947, and the results interpreted in terms of a daily level of flux (near 17h U.T.) and of bursts of noise that may appear during the day.
Preliminary results of radio-astronomical observations of annular solar eclipse, April 19, 1958
Authors: Molchanov A. P. , Fan-Yun Chen , Shou-Kuang Wang , Mirzabekian E. G. , Salomonovich A. E.
Published: July 2016

Radio-astronomical observations of the annular eclipse of 1958 April 19 (η = re/r⊙ = 0.939, ϕ = 18°14′34″.08, λ = −7h18m 01s.86) were especially interesting since this year was, apparently, the year of maximum solar activity. Some preliminary results of the observations carried out by a joint expedition of the Soviet and Chinese Academies of Sciences, equipped with seven radio telescopes, are described in this report.
The transverse motions of the sources of solar radio bursts
Authors: Wild J. P. , Sheridan K. V. , Trent G. H.
Published: July 2016

Observations of the spectrum of solar radio bursts at meter wavelengths have indicated the desirability of measuring positions on the sun's disk not only as a function of time but also as a function of frequency. With this objective in view, we are now using a swept-frequency interferometer to determine the east-west disk coordinate of the transient solar sources at time intervals of ½ second and freqency intervals of about 5 Mc/s within the frequency range 40 to 70 Mc/s. The accuracy to which the centroid of the source is located is about ±1 minute of arc. In its initial form [1], the interferometer contained two aerials separated by a distance of 1 km. As a result of preliminary tests, two major additions have been made: (1) a second interferometer of much smaller spacing (¼ km) has been added to resolve the usual ambiguities associated with two-aerial interferometry, and (2) an automatic system of lobe-switching and phase-calibration has been incorporated to facilitate the reduction of the complex data recorded.
Variations in 18-Mc/s solar and cosmic noise
Authors: Fleischer R.
Published: July 2016

Apparatus for measuring changes in the received intensity of 18–Mc/s cosmic noise has been in operation at the Sampson Station of the Observatory of Rensselaer Polytechnic Institute since 1957 February. It is similar in principle to the equipment of the High Altitude Observatory on which is based the contribution of the Warwicks [1] to this Symposium.
Spectra of short-lived transients in solar noise at 400 Mc/s
Authors: De Groot T.
Published: July 2016

The solar work at the radio observatory near Dwingeloo concentrates on the investigation of relatively small bursts, which, having the aspect of elementary phenomena, could give some insight into the way in which they are related to their immediate cause.
The 1957 November 4 event
Authors: Boischot A. , Fokker A. D.
Published: July 2016

On 1957 November 4, an unprecedented solar radio event was observed at meter wavelengths. Observations at 169 Mc/s were obtained by the Nançay Observatory (great interferometer and simple radio telescope) and by the Humain Observatory. At 200 Mc/s the event was observed by the Nera Observatory.
The first discovery of point sources
Authors: Hey J. S.
Published: July 2016

The investigations into cosmic radio noise that I made with J. W. Phillips and S. J. Parsons arose from operational studies of the performance of radar equipment at about 5-m wavelength in 1944–45. To obtain greater detection ranges, preamplifier stages of low-noise factor were being tested, but they did not result in the expected improvement in radar performance. J. M. C. Scott, a theoretical physicist now at Cambridge, suggested to me that the limitation in effective noise factor might be attributable to cosmic noise, about which something was already known from the work of Jansky and Reber.
The spectra of radio sources
Authors: Whitfield G. R.
Published: July 2016

I have already reported on the spectra of 31 radio sources [1], but since then, new observations have become available, and, in addition, I have corrected my own 38-Mc/s measurements for a nonlinearity in the response of my receiver. The qualitative picture remains the same, but from the more recent information I have found values for the spectral indices of 85 sources, and have revised some of those given previously. From the larger sample of sources now available, it is possible to suggest some relationships of sufficient interest to warrant further investigation.
The structure of the Cassiopeia A and Cygnus A radio sources measured at 127 Mc/s and 3000 Mc/s
Authors: Jennison R. C.
Published: July 2016

The brightness distribution across the Cassiopeia A source in position angle 90 degrees consists of a primary region of emission 4.1 minutes of arc in width, with a much fainter extension offset from the main region of emission and having a brightness of only 10 per cent of that of the main component. Measurements were made up to the third maximum of the transform (2160 λ), and the position of the first zero was determined at 840 λ.
The nature of the radio source Cygnus X
Authors: Drake F. D.
Published: July 2016

The radio source Cygnus X (IAU 20N4A) has long created interest because of its unusual spectrum, its seemingly extended nature, and its location in a region where we believe we look nearly lengthwise down a spiral arm of the Galaxy. Piddington and Minnett [1] first showed that the source had a thermal spectrum. In a recent paper Davies [2] has concluded that the source is an extremely large extended HII region located in the second spiral arm in Cygnus. The recent construction of large parabolic antennas has made it possible to clarify greatly the nature of Cygnus X; it is the purpose of this paper to give the results of a high-resolution survey of the Cygnus X region, and to report a possibly relevant optical observation.
Radio evidence on the large-scale structure of our own and external galaxies
Authors: Pawsey J. L.
Published: July 2016

The subject matter of this session includes both 21-cm and continuum evidence on large-scale features, i.e. features ranging in size from spiral arms to whole galaxies, of our own and of external galaxies. Because the individual papers deal with only some of the separate facets of the subject it is desirable to outline the main lines of investigation and to indicate their interrelations and their physical significance.
A summary and assessment of current 21-cm results concerning spiral and disk structures in our galaxy
Authors: Oort J. H.
Published: July 2016

The results of the survey of the galactic system in the hydrogen line made in the Netherlands have been extensively published and have been discussed at the symposium in Manchester and the I.A.U. assembly in Dublin. I shall not enter into a renewed discussion of these, but rather consider what has been added since.
Galactic structure at meter wavelengths
Authors: Mills B. Y.
Published: July 2016

The study of meter-wave radiation from the Milky Way has been hampered, until recently, by the difficulty of obtaining sufficiently high resolution. Observations using interferometers had early indicated the probability of fine structure in the radiation distribution, but the interpretation of these observations was not unique. It was not until the Sydney 3.5-m cross-type radio telescope (beamwidth 50 minutes of arc) was put into operation in 1954 that it became possible to study the distribution of meter wave emission in detail. The observational program with this instrument, together with most of the data analysis relating to the galactic emission, has now been completed and some of the results have already been described [1, 2]. It seems appropriate at this time to give a rather detailed account of the results of this completed work and to discuss its astronomical and astrophysical significance.
75-cm and 22-cm continuum surveys
Authors: Westerhout G.
Published: July 2016

Continuum surveys were made at 75 cm (400 Mc/s) and 22 cm (1390 Mc/s) with the Dwingeloo 25-m telescope.
A survey of radio sources at 3.5-m wavelength
Authors: Mills B. Y.
Published: July 2016

Since their discovery in 1946, the discrete sources of radio-frequency radiation have provided some of the most difficult problems in radio astronomy. For their effective study, one requires a very highly sensitive radio telescope sufficiently precise for accurate position determination and with sufficient resolution to observe separately the detectable radio sources. These requirements led to the development of the Sydney 3.5-m Cross-type radio telescope, which is a pencil-beam instrument with a beamwidth of about 50 minutes of arc and a sensitivity such that under ideal conditions a source of intensity about 1/10,000 that of the strongest known source, Cassiopeia A, is just detectable.
On the mechanisms of sporadic solar radio emission
Authors: Ginzburg V. L. , Zhelezniakov V. V.
Published: July 2016

The mechanism that generates sporadic (nonthermal) solar radio emission, which is of great interest to radio astronomy and solar physics, is rather obscure. Recently the authors considered this problem [1, 2, 3] and this report gives their summary.
Séance du mardi 2 octobre, matin.: Président de Séance : J. Stock.: Les facteurs météorologiques
Authors: Dommanget J.
Published: July 2016

Les ondes lumineuses émises par les astres doivent nécessairement traverser l'atmosphère terrestre avant de parvenir aux instruments d'observation astronomique. Au cours de cette traversée, divers phénomènes atmosphériques affectent ces ondes aussi bien en ce qui concerne l'énergie qu'elles transportent qu'en ce qui concerne leur forme ou leur orientation. Il surgit ainsi pour l'astronome une série de problèmes particuliers, consistant principalement dans la manière d'éviter au maximum les effets des phénomènes atmosphériques, effets pouvant être désastreux pour la qualité et le rendement des programmes d'observation.
III. — Australie
Authors: Hogg A. R.
Published: July 2016

In 1957 the Joint Observatory of Yale and Columbia Universities commenced a series of site surveys in Australia under the direction of Dr. I. Epstein. While astronomers at Mount Stromlo Observatory were greatly interested in this activity, it was not until 1958 that Mount Stromlo actively commenced site testing. Tests were initiated in the first instance with a desire to find a not-too-distant location suitable for a field station where observing conditions would be better than those at Mount Stromlo, and later with the idea of finding a site anywhere in Australia which would satisfy the needs of a large telescope.
Structure of the Galaxy
Authors: Oort J. H.
Published: July 2016

The title which the organizers of the Symposium have suggested for this introductory report covers an enormous domain. Even if one limits oneself, as I intend to do, to the large-scale structure, it is impossible to summarize this adequately in one communication. I intend therefore to confine myself to give, firstly, a list of principal subjects in which advances have been made and of the main problems which these advances have raised, and, secondly, to comment somewhat more extensively on some points which at the moment appear to be especially important.
The total brightness of galactic clusters
Authors: Buscombe W.
Published: July 2016

For many generations astronomers have been fascinated by open clusters of stars, of which many are found close to the central plane of the Milky Way. Only in comparatively recent years, however, has it become possible to derive reasonably consistent distances for these stellar systems. The difficulty was that until techniques of photoelectric photometry in at least three colours were developed, there were no reliable estimates of the amount of interstellar absorption and reddening.
A high-resolution study of the outer parts of the Galaxy
Authors: Burke B. F. , Turner K. C. , Tuve M. A.
Published: July 2016

The 300-foot transit telescope at the N.R.A.O. at Green Bank, West Virginia, was used in conjunction with the Carnegie 90-channel H-line spectrograph to study the far parts of the Galaxy between l = 11° and l = 50° (lII and bII are to be understood throughout). A travelling feed was constructed at the Carnegie Institution which enabled us to track one point in the sky for approximately 5m40s. This made it possible to make two completely independent frequency scans of a given point each day. On successive days, duplicate curves were taken with the frequency scale shifted, in order to guard against single channel anomalies and pointing error. Line profiles were taken at 160 points in the region under study, in meridional sections every 5° of l, from b = −0°8 to +2°0 in steps of 0°. In addition, a single longitudinal section was taken at b = +0°4 in steps of 1°.
Observation and interpretation of optical and radio polarization
Authors: Westerhout G.
Published: July 2016

Measurements of polarization of radio emission from the galactic background were started in 1957 and seemed to be partially successful, but so uncertain that not much weight was attached to them. Only in the last two years have such polarization measurements been fully successful. They were carried out by radio astronomers at Leiden, Cambridge, and Sydney. I shall report here on the measurements made by the Leiden group, and draw some general conclusions. The first year of observations was described by Westerhout et al. (1962) and Brouw, Muller, and Tinbergen (1962); the work has been continued since by Muller, Brouw, Tinbergen, and Berkhuysen (1963). The observations made by the Cambridge group are substantially in agreement with the Leiden work (Wielebinski, Shakeshaft, and Pauliny-Toth 1962), and so are the Sydney observations, on which Dr. Gardner reports in another paper (this volume, paper 35).
Hydrogen-line observations of the galactic centre region
Authors: Kerr F. J.
Published: July 2016

A detailed study of the galactic centre region is being made with the 210-foot telescope at Parkes and a 48-channel hydrogen-line receiver. Line profiles have been recorded on a 6-min-of-arc grid over a central area 2° square, and also along the galactic equator and a number of other longitude lines. These observations, which have been partially reduced, show that the structure and motions of the gas are very complex in the neighbourhood of the centre.
Distribution des vitesses radiales des regions HII dans la direction du centre galactique
Authors: Courtes G.
Published: July 2016

La Station Française de Zeekoegat (Province du Cap—Afrique du Sud), construite dans le cadre de l'Observatoire Européen Austral est consacrée à l'étude des vitesses radiales par le prisme objectif de Fehrenbach. Parallèlement aux observations du prisme objectif, nous avons, avec P. Cruvellier, conduit un programme d'observations des régions HII de l'Hémisphère Sud.
The role of the Magellanic Clouds in the understanding of galaxies
Authors: Arp H. C.
Published: July 2016

In order to introduce this Symposium on the Magellanic Clouds I feel the most valuable thing I can do is to discuss our understanding of galaxies in general, then show how the Magellanic Clouds in particular fit into the sequence of galactic forms, and finally note a few of the critical problems of galaxies which we might solve by studying the Magellanic Clouds. There are six main points which I wish to mention.
Planetary nebulae and Wolf-Rayet stars in the Magellanic Clouds
Authors: Westerlund B. E.
Published: July 2016

Objects in the Small Magellanic Cloud classified by Lindsay (1961) as planetary nebulae or probable planetary nebulae have been studied in detail on large-scale photographs (Henize and Westerlund 1963). Of Lindsay's 50 objects, 11 are clearly resolved, 2 are probably resolved, 12 show stellar images, 13 are below the limit of the plates, 11 (fairly faint) are outside the photographed regions, and 1 is of uncertain identification. The masses of the resolved nebulae lie between 2 and 33 solar masses. They are therefore classified as small diffuse nebulae; it appears unlikely that the mass of a planetary nebula can exceed a few tenths of a solar mass.
Some problems of objective-prism spectra classification
Authors: Kharadze E. K. , Bartaya R. A.
Published: July 2016

The unique 70-cm meniscus-type telescope of the Abastumani Astrophysical Observatory supplied with two objective prisms and the seeing conditions characteristic at Mount Kanobili (Abastumani) permit us to obtain stellar spectra of a high quality. No additional design to improve the “climate” immediately around the telescope itself is being applied. The dispersions and photographic magnitude limits are 160 and 660Å/mm, and 12–13, respectively. The short-wave end of spectra reaches 3500–3400Å.
Accurate spectral classification by objective-prism techniques
Authors: Bidelman W. P.
Published: July 2016

The performance of moderate dispersion objective-prism equipment, and in particular that of the 10°-prism combination of the Michigan Curtis Schmidt, has been evaluated through a direct comparison of objective prism and slit spectrograms of a number of standard stars. The results suggest that one should seriously consider using objective-prism equipment rather than slit spectrographs for large scale programs of accurate classification of fairly bright stars.

A survey of 171 high-quality Curtis Schmidt plates covering 105 different fields has resulted in the discovery of 46 new peculiar A stars and 66 new metallic-line stars. In addition, 17 stars of later type have been classified as “weak-metal” objects. The most interesting stars detected were HD 3473, which is greatly overabundant in both silicon and magnesium, and the G-type star HD 2665 (mv= 7 · 6), which has subsequently been found to have a radial velocity of approximately – 390 km/sec. This is the brightest star known to have such a large radial velocity.

(The above paper appears in full in the volume entitledBasic Data Pertaining to the Hertzsprung-Russell Diagram, a symposium dedicated to Ejnar Hertzsprung and sponsored by the U.S. Office of Naval Research, to be published by Pergamon Press asVistas in Astronomy, vol. 8).
Some results of the Barbier-Chalonge-Divan system of stellar classification
Authors: Chalonge D.
Published: July 2016

Several years ago a three-parameter system of stellar classification has been proposed (1, 2), for the early-type stars (O-G): it was an improvement on the two-parameter system described by Barbier and Chalonge (3).
Investigation of quantitative classification methods for early-type stars
Authors: Sinnerstad U.
Published: July 2016

As is well known the spectrophotometric methods as introduced by B. Lindblad and developed at the Stockholm and Uppsala Observatories aim at relatively faint stars. The two-dimensional classification in terms of spectral class and absolute magnitude is based on spectrophotometric measures on objective-prism spectrograms of low dispersion (about 200Å/mm). The measures pertain to average intensities in bands having widths of about 30Å.
Equivalent widths of Hγ in the Magellanic Clouds
Authors: Hutchings J. B.
Published: July 2016

J. B. Hutchings has measured equivalent widths of Hγin the large stock of Radcliffe spectra of stars in the Magellanic Clouds. The maximum equivalent width occurs at spectral type Fo due to the very low pressures in the atmospheres of these supergiants. Curves relating equivalent width (reduced to types Ao and B3) with apparent magnitude are presented and agree reasonably well with the corresponding galactic calibration of absolute magnitudes. Among the stars of highest luminosity, measured equivalent widths may be affected by both (a) emission, and (b) presence of expanding shells.

Hutchings has also detected in some of these spectra the presence of 4430Å absorption originative within both Clouds.
Classification spectrale a trois parametres d'etoiles froides par mesure de raies. Application a la determination des abondances en metaux
Authors: Spite F.
Published: July 2016

On connait les succès remarquables remportés par les systèmes de classification quantitatifs. Cependant, jusqu'à présent, de tels systèmes ont surtout été conçus pour des étoiles chaudes. Nous avons donc essayé de voir si la mesure des raies d'absorption sur des spectres à petite dispersion pouvait conduire à une bonne classification des étoiles froides.
Observing programme for the 24-inch/36-inch Schmidt telescope
Authors: Iwanowska W.
Published: July 2016

A new 24-inch/36-inch//3 Schmidt telescope, made by C. Zeiss, Jena, has been installed since 30 August 1962, at the N. Copernicus University Observatory in Toruń. It is equipped with two objective prisms, used separately, one of crown the other of flint glass, each of 5° refracting angle, giving dispersions of 560Å/mm and 250Å/ mm respectively.
A photometric and spectrophotometric investigation of the central parts of the Norma Cloud
Authors: Ramberg J. M.
Published: July 2016

The author has for some time at the Stockholm Observatory been occupied in a photometric and spectrophotometric investigation of the central parts of the Norma Cloud of stars (α = 16h19m5, δ = −52°). The plate material has been collected at the Boyden Observatory: the spectral plates have been secured with the ADH telescope combined with objective prism, the photometric plates with the ADH and the 10-inch Metcalf telescopes. The photographic magnitudes and the colour indices are referred to the photometric system of the E-regions, as established by the Cape Observatory.
Spectrophotometric work on the continua of three very metal-deficient stars
Authors: de Strobel G. Cayrel
Published: July 2016

One of the most interesting abundance determinations of Wallerstein, Greensteinet al.(1) has been the one dealing with three very old population II giants.
Colour-magnitude diagram for two clusterings in the Orion association
Authors: Lodén K.
Published: July 2016

Two subgroups of stars, both close to the Orion Nebula, have been investigated with respect to magnitudes and colours in theUBVsystem. These subgroups are situated (a) around ι Ori (ι Ori clustering) and (b) just to the north of the small nebulosity around 42 and 43 Ori (Northern Sword clustering). There seems to be no doubt of the physical connection between the stars in each group. Charts showing the investigated stars are given in a paper by W. W. Morgan and K. Lodén (1).
The Ratio of Total to Selective Extinction in the Directions of Selected Planetary Nebulae
Authors: Lutz Julie H.
Published: July 2016

The ratio of total to selective extinction has been determined for the lines-of-sight to six planetary nebulae.
Interstellar Dust: Observations in the Ultraviolet and Their Interpretations
Authors: Witt Adolf N.
Published: July 2016

Recent observations of interstellar extinction and diffuse galactic light in the ultraviolet are interpreted in terms of a bi-modal size distribution of interstellar grains.
Polarization Profile Near the 4430 Band
Authors: Nandy K. , Seddon H.
Published: July 2016

It has been reported by several authors that the extinction profile near the wavelengths of unidentified diffuse features shows fine structure (Brück and Nandy, 1970; Walker, 1971; York, 1971; Bromage, 1972); the question arises whether these features also exhibit fine structure in wavelength dependence of polarisation. It was first suggested by Greenberg et al. (1970, 1971) that interstellar bands produced by grain impurities may be polarized differently from the neighbouring continuum. Similar conclusions were also derived by Wickramasinghe and Nandy (1971) and Kelly (1971). Our first attempt to derive a profile of polarization against wavelength across the 4430 Å band was reported earlier (Nandy and Seddon, 1970). In this method we have used a Wollaston prism at the Cassegrain focus of the 36″ Telescope of the Royal Observatory, Edinburgh to produce orthogonally polarised spectra on the photographic plate. The results for the star 55 Cyg (Figure 1) indicated a definite profile. It was felt than an extension of the programme to acquire further profiles and to establish instrumental polarisation to a greater accuracy was necessary.
Interstellar Polarization
Authors: Serkowski K.
Published: July 2016

A review of observational data on interstellar polarization is given. The degree of fluctuation in the direction of the galactic magnetic field is discussed. An empirical formula is given which fits all the observations of the wavelength dependence of interstellar polarization when they are normalized with the wavelength λmax of maximum polarization. Well-defined regions on the sky with values of λmax deviating from an average are found. Values of λmax are correlated with the ratio of total to selective interstellar extinction. A unified wavelength dependence of interstellar extinction is obtained by normalizing the observations with the wavelength λmax of maximum interstellar polarization.
Discovery of Interstellar Circular Polarization in the Direction of the Crab Nebula
Authors: Martin P. G. , Illing R. , Angel J. R. P.
Published: July 2016

A search in many small regions of the Crab Nebula has resulted in the detection of a small component of circular polarization. The variation of the sign and magnitude with position in the Nebula indicates that the polarization is of interstellar origin. On the basis of the polarity, strength, and colour dependence, it is concluded that the composition of the aligned grains causing this polarization is dielectric. Metallic particles are clearly ruled out.
Dust and Neutral Hydrogen in the Region of IC 1396
Authors: Simonson S. Christian
Published: July 2016

A 21-cm survey at Dwingeloo of a 5° square containing IC 1396 shows several neutral hydrogen concentrations that correspond in shape and position with dust clouds, particularly the bright-rimmed clouds involved with the H II region.
A Laboratory Experiment on the Nucleation of Interstellar Dusts
Authors: Kamijo F. , Nakada Y. , Iguchi T. , Fujimoto M. , Takada M. , Takajo S.
Published: July 2016

Small particles of silica, carbon, and iron are produced in the laboratory for the eventual purpose of studying their optical properties.
Exploding Interstellar Grains and Complex Molecules
Authors: Greenberg J. Mayo , Yencha Andrew J.
Published: July 2016

The triggering of an explosive chemical reaction in a grain which consists of free radicals frozen in a matrix of photolyzed dirty ice material is seen as a possible source of complex interstellar organic molecules.
Stellar Atmospheres: The Sources of Interstellar Molecules
Authors: Shimizu Mikio
Published: July 2016

The analysis of the abundance of interstellar molecules in compact H II regions suggests that the molecules are formed in stellar atmospheres (possibly of protostars or of late type stars), transported to the location of the neutral clouds in the cpmpact H II regions, and shielded from decomposition due to stellar radiation by the dust in the clouds. Cometary nuclei and interstellar dust are argued from the astrochemical point of view to be dirty ice of the second kind (or a sort of frozen interstellar molecules). The chemical structure of the primordial solar nebula is discussed under the assumption that long-period comets consist of the most primordial substances of the solar system.
Interferometric Studies of OH Sources Associated with H II Regions and IR Objects
Authors: Davies R. D.
Published: July 2016

An interferometer with a 24 km baseline has been used to map components of OH sources to a precision of a few hundredths of a second of arc. The W3 OH source which is associated with an H II region appears to be rotating slowly. There is evidence for Zeeman splitting in the components of this source. The IR/OH sources NML Cygnus and VY CMa are found to be expanding objects with a large rate of mass outflow. Rotation is also evident in both these objects.
Dust in H II Regions
Authors: Petrosian Vahe
Published: July 2016

The observed far infrared flux of H II regions is interpreted as evidence for the presence of internal dust absorbing a fraction of Lyman continuum photons. The effect of this dust on the required number of ionizing photons and on the helium to hydrogen line intensity ratios are discussed and analytic formulae describing these effects are presented for simplified models.
Dust in the Large Magellanic Cloud
Authors: Johnson Hugh M.
Published: July 2016

A brief review of extinction effects is followed by a discussion of new Cerro Tololo Schmidt plates. They were exposed on parts of the LMC with filters which reveal the presence or absence of a continuum, such as one scattered on dust, in H ii regions. The results are presented in comparison with the Orion nebula which was observed in the same way. The continuum is always relatively weak in those LMC H ii regions which are significantly larger than Orion, but the continuum averages strong in the Orion-class and point-image nebulae.
The Mixing of Neutral Gas and Dust with the Ionized Gas of H II Regions
Authors: Lortet-Zuckermann M. C.
Published: July 2016

Two arguments are presented in support of the now well-established fact of the tight mixing of neutral gas and dust with the ionized gas of H II regions.
Rocket Measurements of the Galactic Background at 100 μ
Authors: Pipher Judith L.
Published: July 2016

Measurements of the diffuse background radiation in the 85–115 μ band are presented, as observed from altitudes close to 190 km with a rocket-borne, liquid helium cooled telescope. Evidence is given for detection of the galactic background due to thermal grain emission at galactic latitudes of 5–35°, and at a galactic longitude of ~ 163°. At small latitudes, the background intensity is measured to be ~ 9 × 10–11 W cm–2 sr–1; the average number density of grains derived is consistent with the optically determined measure. The 100 μ data is compared with 20 μ data taken on the same flight, in order to draw some conclusions about the grain emissivity and temperature.
Type Ib/c Supernovae and their Relation to Binary Stars
Authors: Leibundgut Bruno
Published: July 2016

The present understanding of type Ib/c supernovae and their connection to interacting binaries is reviewed. The problems of the classification and the lack of well-observed events exclude direct inference of progenitor characteristics. The absence of hydrogen lines in the observed spectrum, nevertheless, requires restricted evolutionary schemes to produce suitable progenitor stars for core collapse explosions with no hydrogen envelope. New relative statistics among the supernova types are presented which indicate that SN Ib/c are on average brighter than SN II, and with the dense sampling of supernova searches in nearby galaxies, a small intrinsic incidence of SN Ib/c is determined. The small rates might be in conflict with the observed ratio of massive stars in binaries in the Galaxy.
Timing of Millisecond Pulsars
Authors: Backer D. C.
Published: July 2016

Arrival times of some millisecond pulsars can be measured with sub-microsecond precision. This allows unprecedented measurements of the rotation of these stars, astrometric parameters including proper motion and parallax, motion in binary and complex dynamical systems, perturbations resulting from propagation through small scale turbulence in the interstellar plasma and other effects. In addition to the independent parameters which are required to model each pulsar, there is a set of global parameters that affect the array of pulsars in a correlated manner. These parameters involve the international atomic time scale, the ephemeris of the Earth's orbit and the gravitational wave background and have monopole, dipole and quadrupole and higher order angular signatures, respectively.
The Radio Outburst from GRO J1655-40
Authors: Hunstead R.W. , Campbell-Wilson D. , Ye T.
Published: July 2016

Strong variable radio emission from the bright transient X-ray source GRO J1655-40 (X-ray Nova Scorpii 1994) has been detected at 843 MHz with the Molonglo Observatory Synthesis Telescope (MOST). As the hard X-ray intensity from the 1994 August outburst declined the radio output increased rapidly, reaching a peak of nearly 8 Jy some 12 days after the first X-ray peak. VLBI images obtained at this time showed two main components separating with an apparent transverse velocity > c. The evolution of the radio spectrum suggests that the time delay between X-ray and radio emissions is due, at least in part, to opacity effects associated with this expansion.
Are Supersoft X-ray Sources Consistent with White Dwarfs?
Authors: Teeseling A. Van , Heise J. , Kahabka P.
Published: July 2016

Van den Heuvel et al. (1992) argued that the emission from supersoft X-ray sources can be explained by steady nuclear burning of hydrogen accreted onto massive white dwarfs. An argument that has been used against this model is that the bolometric luminosities inferred from blackbody fits are sometimes above the Eddington luminosity of a ∼1 M⊙ star. However, hot white dwarfs don't radiate blackbody spectra (Heise et al. 1994). Therefore, we have calculated model spectra for hot (accreting) white dwarfs, and investigated whether the emission from supersoft X-ray sources is consistent with an origin from white dwarfs. Here we summarize some preliminary results. For a review of supersoft X-ray sources we refer to the contribution of Kahabka & Trümper to these proceedings.
Analysis of Long-Term AAVSO Observations of RS Ophiuchi
Authors: Oppenheimer B.D. , Mattei J.A.
Published: July 2016

We present here a study of the five reported outbursts of the recurrent nova RS Ophiuchi, together with an analysis of its light variation between outbursts. We find that the shapes and decline rates of the outbursts are strikingly similar to each other. We note the possibility of an additional, unreported outburst in 1945, supported by the similarity of its decline to that of other outbursts. Each interval between outbursts shows periodicity within itself, however, there is no periodicity common to all, and the possible periods range between 892 and 2283 days.
Present status of the Taiwan Oscillation Network
Authors: Chou Dean-Yi ,   The Ton Team
Published: July 2016

The Taiwan Oscillation Network (TON) is a ground-based network measuring solar intensity oscillations for the study of the internal structure of the Sun. So far, four telescopes have been installed at Teide Observatory (Tenerife), Huairou Solar Observing Station (near Beijing), Big Bear Solar Observatory (California), and Tashkent (Uzbekistan). The TON telescopes take K-line full-disk solar images of diameter 1000 pixels at a rate of one image per minute. The TON high-resolution data is specially suitable to study local helioseismology. Here, we present recent results of three topics on local helioseismology from TON data: (1) Inference of Subsurface Magnetic Field From Absorption Coefficients of p-modes in Active Regions, (2) Subsurface Structure of Emerging Flux Regions From Helioseismology, and (3) Flow Around Sunspots From Measurements of Frequency Shift.
Plane-wave analysis of SOI data
Authors: Bogart R. S. , Discher De Sá L. A. , Hernández I. González , Recio J. Patrón , Haber D. A. , Toomre J. , Hill F. , Rhodes E. J. , Xue Y. ,   The SOI Ring Diagrams Team
Published: July 2016

The unprecedented combination of spatial resolution and stability achieved by the Solar Oscillations Investigation/Michelson Doppler Imager on SOHO has opened up new opportunities for the analysis of solar surface oscillations of high spatial frequencies. In this regime the oscillations are essentially plane waves, amenable to the techniques of ring-diagram analysis of their three-dimensional power spectra. This approach holds the promise of measuring fluid motions and possibly magnetic fields in spatially-resolved structures within the uppermost levels of the convective envelope, a region unresolved by the global modes. Atmospheric g-modes trapped above the photosphere may also be detectable. We review the first results of plane-wave analysis of various types of SOI data and comparisons with the analyses of comparable ground-based datasets.
Making a seismic solar model and an estimate of the neutrino fluxes
Authors: Shibahashi H. , Takata M.
Published: July 2016

We present a method of making a solar model based on the helioseismic data. We first invert the observed eigenfrequencies to determine the sound speed profile, and then solve the basic equations governing the stellar structure with the imposition of the determined sound-speed profile. This approach is different from that of the standard solar model in the sense that the ‘seismic’ solar model is a snapshot model of the sun constructed without any assumption about the history of the sun. We invert the data obtained at the South Pole by the Bartol/NSO/NASA group along with BISON, HLH, and LOWL data. Finally we estimate the neutrino fluxes of the seismic model.
Internal structure and rotation of the Sun: First results from the MDI data
Authors: Kosovichev A.G. , Schou J. , Scherrer P.H. , Bogart R.S. , Bush R.I. , Hoeksema J.T. , Aloise J. , Bacon L. , Burnette A. , Forest C. De , Giles P.M. , Leibrand K. , Nigam R. , Rubin M. , Scott K. , Williams S.D. , Basu Sarbani , Christensen-Dalsgaard J. , Däppen W. , Rhodes E.J. , Duvall T.L. , Howe R. , Thompson M.J. , Gough D.O. , Sekii T. , Toomre J. , Tarbell T.D. , Title A.M. , Mathur D. , Morrison M. , Saba J.L.R. , Wolfson C.J. , Zayer I. , Milford P.N.
Published: July 2016

The Medium-l Program of the Michelson Doppler Imager (MDI) instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to ∼ 300. The initial results show that the noise in the Medium-l oscillation power spectrum is substantially lower than in ground-based measurements. This enables us to detect lower amplitude modes and, thus, to extend the range of measured mode frequencies. The MDI observations also reveal the asymmetry of oscillation spectral lines. The line asymmetries agree with the theory of mode excitation by acoustic sources localized in the upper convective boundary layer. The sound-speed profile inferred from the mean frequencies gives evidence for a sharp variation at the edge of the energy-generating core. In a thin layer just beneath the convection zone, helium appears to be less abundant than predicted by theory. Inverting the multiplet frequency splittings from MDI, we detect significant rotational shear in this thin layer.
Sounding solar and stellar interiors: Conclusions and prospects
Authors: Gough Douglas
Published: July 2016

I have been charged to summarize the mood of the symposium, although not to summarize the scientific details, for they are best learned by reading the proceedings. To the best of my ability, I shall comment on those details in a manner that Philippe Delache might spontaneously have done had it not been incumbent upon him to cover everything. Therefore I shall be somewhat personal. I shall make no attempt to offer a balanced view of the observations and calculations that have been reported, but instead concentrate on how they might be viewed. In so doing I bear in mind that Philippe was not one to tow the party line. He often ignored the democratic means by which unfortunately so-called scientific truth is too often established today, and instead showed more interest in the unusual. Although such behaviour can sometimes lead one into danger, as it did with regard to Philippe's proposed explanation of the infamous 160-minute oscillation of the sun (Arvonny, 1983), it is also the most common road to true discovery.
Turbulent Mixing Layers in Herbig-Haro and Embedded H2 Jets
Authors: Noriega-Crespo Alberto
Published: July 2016

Outflows arising from young stellar objects interact with their surrounding medium through different mechanisms, such as shocks, turbulence and /or entrainment. These two last mechanisms have recently begun to be fully developed in an effort to understand the coupling of the stellar jet gas (mostly atomic) with the molecular environment. Observationally a number of objects are being studied in the near infrared and millimeter wavelengths to map the warm (H2) and cold (CO) molecular gas, respectively. In this paper we discuss some of the properties in the near infrared of various embedded jets in the context of turbulent entrainment.
The Physics of Molecular Shocks in YSO Outflows
Authors: Hollenbach David
Published: July 2016

Shock waves light up the jets, winds and outflows around YSOs and diagnose the physical conditions and processes resident in these regions. This paper discusses the differences between the jet/wind shock and the ambient shock, between C shocks and J shocks, and between the shocks produced by pure jets and by collimated wide angle winds. Basic shock physics is briefly reviewed, with a special focus on the temperature structure in shocks and the Wardle instability of C shocks. Application is made to the origin of shocked H2 emission and to H2O masers.
The Class 0 Outflow Hammered Out?
Authors: Smith Michael D. , Völker Roland , Suttner Gerhard , Yorke Harold W.
Published: July 2016

Dense molecular jets cutting through dense molecular clouds are simulated here using a ZEUS-type hydrodynamics code extended with molecular physics. H2 ‘hot snapshots’ and CO ‘historical views’ are nicely modelled with overdense uniform jets. Attention is drawn to some remaining hot problems: observed jet knots are bow shaped, bipolar outflows can be highly asymmetric, some proper motions within jets are enigmatically low and H2 excitation can be exceedingly uniform.

We present the Hammer Jet, in which the nozzle introduces high velocity variations, as well as a strong ripping and spray action. Prominent jet bow shocks in H2 and CO emission lines are then produced. Wide tubular CO structures with concave bases show up. Proper motions are simulated. The asymmetries are modelled by jet break-out from a molecular core into a diffuse atomic environment.
The Radiative Impact of FU Orionis Outbursts on Protostellar Envelopes
Authors: Bell K. R. , Chick K. M.
Published: July 2016

We present preliminary results of an investigation into the radiative impact of FU Orionis outbursts on protostellar envelopes. In the thermal accretion disk instability model, the inner portion of the disk is inflated in such a way as to funnel most of the outburst luminosity along the poles of the system. A multidimensional radiative transfer code is employed to derive the thermal equilibrium structure of the surrounding protostellar envelope and the backheated accretion disk during outburst. The radiation emitted during outburst is modeled as a combination of a self-luminous accretion disk and a central point source. We compare the relative heating of circumstellar material due to (1) an isotropic point source and (2) an anisotropic point source in which the emitted radiation is confined to a 30° cone about the polar axis. The isotropic point source creates a spherical dust cavity, while the anisotropic source naturally results in a cavity which is hourglass-shaped. Repeated outbursts may ultimately be responsible for the large-scale polar cavities commonly inferred to exist around young stellar objects. We also show that due to the anisotropy of the radiation expected during outburst, disk annuli within a few au will be shielded from the radiation of the outburst.
The Period Distribution of Close Binary Systems
Authors: Mantegazza L. , Paolicchi P. , Farinella P. , Luzny F.
Published: July 2016

The analysis of the period distribution of eclipsing and spectroscopic binary systems shows the presence of some secundary maxima, which cannot depend on selection effects. These secundary maxima are mainly due to late type stars, as can be seen from the distribution curves for eclipsing binaries of various spectral types. The average separation of the components (in units of the sum of stellar radii) increases with the spectral type from 0 types to late B types, remaining almost constant for later spectral types.
The Effect of Orbital Eccentricity on Polarimetric Binary Diagnostics
Authors: Aspin C. , Brown J. C. , Simmons J. F. L.
Published: July 2016

The polarimetric variation from a binary system with an eccentric orbit, thus non-corotating, are calculated and the effect on determining the system parameters is discussed, relative to the circular case.