bluuebunny/crossref_metadata_2025 huggingface dataset:
The compiled catalogue of galaxies in machine-readable form and its statistical investigation
Authors: Kogoshvili N.G.
Published: July 2016

The compilation of a machine-readable catalogue of relatively bright galaxies was undertaken in Abastumani Astrophysical Observatory (Kogoshvili 1972; 1975) in order to facilitate the statistical analysis of a large observational material on galaxies from the Palomar Sky Survey. This catalogue is mainly based on the data from the MCG catalogue (Vorontsov-Veljaminov et al, 1962-1968) supplied with information from the UGC (Nilson, 1973), RCBG (De Vaucouleurs and De Vaucouleurs, 1964), CGCG catalogues (Zwicky et al, 1961-1968) and from other sources.
Geneva photometric boxes. IV. A refined method for direct access
Authors: Nicolet Bernard
Published: July 2016

In the Geneva photometry, a photometric box around a so-called central star is the set of stars having almost the same colours as this central star.

For the most current applications, it is useful to construct the boxes of a few hundred stars. A method allowing to obtain these boxes rapidly is described. It is based on socalled direct access square files. A FORTRAN routine on a UNIVAC 1160 computer is widely used at the Geneva Observatory. The principles described in this paper may be easily adapted to build square files and to write routines in evolved languages for most computers.

Other applications of square files are also outlined.
The Zelenchuk 6m Telescope (BTA) of the USSR Academy of Sciences
Authors: Ioannisiani B.K. , Neplokhov E.M. , Kopylov I.M. , Rylov V.S. , Snezhko L.I.
Published: July 2016

A description is given of the alt-azimuth mounted 6-meter telescope (BTA) installed in the North Caucasus at an altitude of 2070m above sea level and about 40km to the south of Zelenchukskaya village. Some details of the BTA instrumentation and the local astroclimate are also reported.
An Integral Field Spectrograph (IFS) for Large Telescopes
Authors: Courtes G.
Published: July 2016

A combination of an array of small lenses together with fibre optics can be used to produce a high transmission spectrograph which can record the spectra of many image elements simultaneously. Such a design may play an important role in ground based observations preparing for the NASA-ESA Space Telescope programmes.
A Photometric System to Search for Optical Variability on Time-scales of 3 x 10-7 to 300s: Main Results
Authors: Beskin G.M. , Neizvestnyi S.I. , Pimonov A.A. , Plakhotnichenko V.L. , Shvartsman V.F.
Published: July 2016

One of the basic astrophysical problems is to search for and investigate brightness fluctuations of celestial objects at times comparable with the mean time between registered photons. With that end in view, a special mathematical formalism has been developed in recent years (Shvartsman, 1977; Pimonov and Terebizh, 1981; Plakhotnichenko, 1980).
Spectroscopy with Photon-Counting Reticons
Authors: Latham David W.
Published: July 2016

Since 1978 we have been using photon-counting Reticons for spectroscopy at Mt. Hopkins. With these detectors we have accumulated approximately 50,000 exposures, resulting in nearly 10,000 reduced astronomical spectra. This paper describes the performance of the detectors, discusses some of the procedures we use for remote observing, outlines the magnitude of the data-handling problem, and gives a few examples of recent results.
Statistical test of the distribution of perihelion points and its implication for cometary origin
Authors: Yabushita S.
Published: July 2016

The distribution of perihelion points of long-period comets is known to cluster towards the solar apex, and some authors ascribe it to north-south asymmetry in the distribution of observers. Validity or otherwise of this alleged selection effect is tested by randomly picking up the same number of perihelia in the southern (δ < 0) as those in the northern (δ > 0) hemisphere. It is shown that the observed clustering cannot be ascribed to the asymmetry of observers. Further, 67 comets which are new in Oort’s sense are tested similary. The character of their distribution is similar to that of all the known comets. It appears difficult to interpret the clustering in terms of a recent stellar disturbance of the Oort cloud.
Dynamical interactions of the solar system with massive nebulae
Authors: Napier W.M.
Published: July 2016

The effects of encounters with massive nebulae on the long-period comet population are examined, paying particular attention to the uncertainties in the data. An earlier conclusion, that the long-period comet system is dynamically unstable, is upheld. Whether replenishment by unbinding from a dense inner comet cloud is a viable hypothesis awaits detailed modelling, but a qualitative discussion is given which argues tentatively against it. If comets occur in molecular clouds, however, their capture into temporarily bound Solar System orbits is a natural consequence of close encounters for realistic velocities and potentials. A large disturbance or capture may have occurred a few Myr ago as the Sun emerged from the Orion spiral arm.
The dynamical history of comet Halley
Authors: Yeomans Donald K.
Published: July 2016

The history of the attempts to predict the motion of comet Halley is outlined and the importance of the so-called nongravitational forces acting upon this comet is emphasized. Recent orbital work of the International Halley Watch Astrometry Network is reviewed. Comet Halley’s transverse nongravitational parameter is positive and nearly constant with time suggesting that the comet is in direct rotation without precession of the spin pole. The nongravitational effects are consistent with the vaporization of water ice from the comet’s nucleus and long term integrations suggest that the comet has been in its present orbit for at least 16,000 years and probably much longer.
Photographic Observations of the Inner Zodiacal Light Aboard Saliout 7
Authors: Nikolsky G. , Koutchmy S. , Lamy P.L. , Nesmjanovich I.A.
Published: July 2016

Color photographs of the inner Zodiacal Light were obtained aboard Saliout 7 with Kodak Ekta 400. Absolute calibrations were performed in-Flight with attenuated Sun light. The photometric analysis was carried out in three colors and corrections were introduced for the 01 emission of the F layers. The brightness of the Zodiacal Light along the ecliptic is found in good agreement with published data while its color is found slightly redder than the Sun. Its out-of-ecliptic variation coincides neither with the fan nor the ellipsoidal model; the photometric axis is found near the projection of the orbital plane of Venus.
An Observational Search for the Schuerman Dust Arcs
Authors: Giovane F. , Weinberg J.L. , Mann H.M. , Oliver J.P.
Published: July 2016

Large-scale interplanetary dust arcs were predicted by Schuerman (1980) to be associated with the planets. An arc, if one exists, would produce asymmetries on opposite sides of the Gegenschein during the Earth’s two passages through the arc each year. A brief description is given of Gegenschein/arc observing constraints, of future viewing opportunities, and of the results of a test program conducted from Mt. Haleakala, Hawaii, in Jan/Feb 1984 when the Earth encountered the arc associated with Saturn.
A Coronascanner for a Sun Oriented Space Mission
Authors: Koutchmy S. , Lamy P.L.
Published: July 2016

The quantitative study of the solar corona between 3 and 20 R⊙ is still a challenging task. Inherent difficulties are the proximity of the Sun and the still bright inner corona (< 3 R⊙), the low brightness of the outer corona and the low contrast of possible structures. A spinning, externally-occulted coronograph having its field-of-view limited to a sector of the corona presents several advantages over conventional coronographs for this study such as higher rejection of stray light and azimuthal uniformity over the whole field-of-view. Such an instrument could address the following aspects of the F-corona:

– photopolarimetry and colorimetry

– ellipticity, axis of symmetry

– temporal/spatial variations

– equatorial enhancements (rings)

– local component.
Influence of Surface Roughness on Scattering Patterns
Authors: Mukai S. , Mukai T.
Published: July 2016

The influence of surface roughness on scattering properties of light is examined in terms of our previous mathematical method (Mukai et al. 1982). We found that albedo for single reflected light increases with an increase of surface roughness. In addition, a higher order of reflection light becomes effective for stronger rough particles.
Selection Effects Against Small Comets
Authors: Zook H.A. , Fernández J.A. , Grün E.
Published: July 2016

There are three factors that inhibit detecting small comets relative to large comets: 1. They must pass closer to the Earth than large comets to be detected. 2. The resulting higher angular velocity for nearby comets means that, at comparable apparent magnitudes, there is less time available to discover a small comet relative to a large comet. 3. Small comets physically decay and vanish faster than do large comets. With these three factors, it can be shown that if the small comet input distribution gi (Rn) in varies as , where Rn is the nuclear radius of the comet, then the observed distribution will vary as
Interaction of the Cometary Dust with the Solar Wind and Cometary Plasma
Authors: Ip W.-H. , Kimura H. , Liu C.-P.
Published: July 2016

Along the lines of previous studies on the cometary dust-plasma interaction processes, we evaluate the electromagnetic effect of submicron dust in the coma and in the dust tail. The possible occurence of electrostatic disruption of charged dust in the ion tail is also discussed from theoretical and observational points of view. The relevance of these processes to the formation of striae in the dust tails of several comets is addressed and the conclusion is made that trajectory study of the submicron dust in the striae must take into account the action of the interplanetary electric field.
Optical and Photoelectric Properties of Materials of Astrophysical Interest
Authors: Quemerais A. , Seignac A. , Priol M. , Lefèvre J.
Published: July 2016

The charge of cosmic grains can be calculated if the optical constants, the photoelectric yields and the photoelectron energy distributions for a large range of energy of incident photons are known. Our measurements are made on several materials which are possible constituents of interstellar and interplanetary dusts. We present here our results for fused quartz, iron and carbon.
Laboratory Simulation of Chemical Interactions of Accelerated Ions with Dust and Ice Grains
Authors: Rössler K.
Published: July 2016

Energetic ions or atoms in space may undergo hot chemical reactions upon penetration into interplanetary or interstellar dust grains, ice layers, cometary matter, and surfaces of planetary moons. The mechanistic pathways can be different from those of classical ion molecule interactions, photolytical and radiolytical processes. The kinetic energy of the hot reactant facilitates endothermic reactions and those with high energy of activation, among them atom-molecule interactions. The conditions of hot cosmic chemistry are simulated in laboratory experiments in order to obtain insight into the nature of chemical products and the reaction mechanisms of their formation. This paper reviews the methods of ion implantation, nuclear recoil in situ, nuclear recoil implantation, secondary knock-on processes and computer simulation of collision cascades. Carbon and nitrogen impact in frozen H2O, NH3 and CH4 is shown to lead to the formation and radiolytic permutation of a series of organic molecules, among them e.g. formaldehyde, methanol, methylamine, cyanamide, formamidine and guanidine which may act as precursors for biomolecules.
Summary and Conclusion of the Colloquium
Authors: Lamy P.L.
Published: July 2016

There is now a satisfactory convergence of the observational results for the absolute intensity of the zodiacal light for elongations larger than 20° to 30°. They are still discrepancies affecting the data for the F-corona but after carefully scrutinizing available data, Koutchmy and Lamy could obtain an axy-asymmetric non-spherical model for the equatorial and polar regions which satisfactorily bridges to the zodiacal light. However, a closer examination reveals several points of concern:

i)

the gradient of the brightness which is of utmost importance for retrieving the phase function of interplanetary dust: the “Hawaï” data (Misconi and Weinberg), the PCN data (Nikolsky et al.) and the classical data of Dumont and Sanchez are in disagreement;

ii)

a lack of data for the inner zodiacal light;

iii)

insufficient out-of-ecliptic data; the on-going analysis of the “Hawaï” data (which benefits from an improved reduction method) and of the “South Africa” data will help partly remedy this situation. A consensus appears to be reached on the near solar color of the zodiacal light or, to be more precise, a slight reddening down to 2000 Å. The inner zodiacal light and the F-corona are clearly redder than the Sun. Some structure near 2800 Å reported by Feldman et al. is certainly worth of further investigation. Ultraviolet observations of Comet Halley may well provide adequate opportunities. The situation of the polarization of the zodiacal light is less satisfactory as large discrepancies persist. Of major importance for the properties of the dust grains are the behaviours at small and large scattering angles - in particular, the shape of the negative branch - as well as the angle of maximum polarization and its magnitude. The polarization is certainly color dependent but the present data are insufficient for a clear-cut conclusion.
Derivation of the Ionization Balance for Iron XIV/XXV and XXIII/XXIV Using Solar X-Ray Data
Authors: Antonucci E. , Dodero M.A. , Gabriel A.H. , Tanaka K.
Published: July 2016

The relative concentrations of different ionization stages of iron are measured using the spectral emission of plasmas formed during solar flares. This is an extension of a study on the ionization balance of heavy elements, initiated with the analysis of calcium solar spectra (Antonucci et al., 1984). The data consist of a large set of iron spectra in the wavelength range from 1.84 to 1.88 Å, detected during the recent maximum of activity with the X-ray Polychromator Bent Crystal Spectrometer (BCS) on the NASA Solar Maximum Mission satellite and on the Soft X-ray Crystal Spectrometer (SOX) on the Hinotori satellite.

At the low densities typical of the solar corona, in the steady state the ionization balance of an element is a function of the plasma electron temperature. Hence, it can be measured for plasmas of known temperature and in slowly varying physical conditions, and in most cases, solar flare plasmas can be considered to be in such conditions.
Variation of the Observed Coronal Calcium Abundance for Various X-Ray Flare Plasmas
Authors: Sylwester J. , Lemen J.R. , Mewe R.
Published: July 2016

We present the first observational evidence for the variation of the coronal calcium abundance in the high-temperature solar flare plasmas. The analyzed data consists of the X-ray flare spectra observed by the Solar Maximum Mission satellite with the Bent Crystal Spectrometer. From BCS spectra we derived the ratio of the line to continuum flux IL/IC for the resonance line of Ca XIX λ = 3.1781Å and the continuum at the same wavelength as a function of the temperature. The studies of 13 flares showed similar temperature dependence during the decay phases, but the agreement of the IL/IC ratio from flare to flare could only be achieved by adjusting an overall normalization factor. As the continuum flux depends weakly on the heavy elemental abundance, this variation of the IL/IC ratio can be attributed to the variation in the calcium abundance. For the flares considered, the variation between the extreme cases represented the factor of 2.5. We stress the consequences of the observed abundance variation for the analysis and interpretation of XUV and X-ray spectra.
The Relevancy of Magnetically Confined Plasmas - Tokamak and Mirror - for Atomic Spectroscopy And Astrophysical Plasma Diagnostics
Authors: Finkenthal M.
Published: July 2016

This talk presented the magnetic confinement experiments from a different angle, i.e. as laboratory sources which allow the study of various problems in such fields as atomic physics and astrophysics.

Tokamak and magnetic mirror plasmas have properties which make them particularly suitable for basic atomic physics experiments; they are stable over long intervals of time and have wide ranges of electrom densities and temperatures. Also, models on which electron density and temperature diagnostics are based in astrophysical research can be checked since these quantities are accurately measured by independent non-spectroscopic methods.
Observation of Ionization of Laser Excited Atoms by Synchrotron Radiation
Authors: Bizau J.M. , Wuilleumier F. , Gerard P. , Dhez P. , Carré B. , Spiess G. , Ederer D.L. , Picqué J.L. , LeGouet J.L. , Keller J.C. , Koch P.
Published: July 2016

We have begun a program to measure oscillator strengths of autoionizing resonances that result from a transition in the VUV between a laser excited initial state and a final state in which a core electron is promoted. These measurements demonstrate a new technique to combine synchrotron radiation, laser pumping, and photoelectron spectroscopy.

Measurements of the energy positions of autoionizing resonances have been honed to a fine art over the past 50 years. Total cross section measurements and the parameters that describe autoionizing resonances have been determined. Most of these studies have been made from the dipole allowed ground state. Recently autoionizing resonances have been observed from excited initial states and from ion initial states. We have heard several talks, at this meeting which described some of this type of research. In the measurements to be described in this paper, laser radiation is combined with synchrotron radiation, as shown schematicaly in Figure 1, to study the photoionization from excited initial states to continuum final states or to autoionizing final states. Continuum radiation from the Aneau de Collisions d’Orsay (ACO), which is installed at the Universite de Paris-Sud, in Orsay France, is monochromatized by a toroidal grating monochromator (TGM) and is focused by a toroidal output mirror on to a weakly collimated sodium beam emanating from a furnace mounted on the axis of a cylinderical mirror analyzer (CMA). This electron spectrometer is used to study the kinetic energy distribution of the ejected photoelectrons produced by the interaction of the photon beam with the focused synchrotron radiation.
Analysis of Intensity Ratio for MgXII Lyα Components from Intercosmos 7 Observations
Authors: Sylwester J. , Sylwester B. , Jakimiec J. , Tomczak M. , Mandelstam S.L. , Zhitnik I.A. , Korneev V.V.
Published: July 2016

We discuss the Mg XII Lyα line profile measurements obtained, by means of Bragg crystal spectrometer aboard INTERCOSMOS 7 satellite. The design of this spectrometer allows to clearly resolve both components α½ and α3/2) of the Lyα spin doublet. The intensities of each of these components we derived by means of fitting two Voigt profiles to the measured Mg XII Lyα shape. More than 100 spectra were analyzed in this way providing the statistical information on the value of intensity ratio . Derived average value of a is close to the theoretically expected 0.5, but in many cases the value of a is significantly different from 0.5 (both lower and higher values occur). We present examples of the fit and the histograms showing correlations of a value with the values of other flare parameters. Present analysis consist the observational part of the larger paper under the preparation with Prof. R.W.P. McWhirter theoretical group.
The Solar and Heliospheric Observatory
Authors: Noci Giancarlo
Published: July 2016

In the past years several space missions have been proposed for the study of the Sun and of the Heliosphere. These missions were intended to clarify various different aspects of solar physics. For example, the GRIST (Grazing Incidence Solar Telescope) mission was intended as a means to improve our knowledge of the upper transition region and low corona through the detection of the solar EUV spectrum with a spatial resolution larger than in previous missions; the DISCO (Dual Spectral Irradiance and Solar Constant Orbiter) and SDO (Solar Dynamics Observatory) missions were proposed to gat observational data about the solar oscillations better than those obtained from ground based instruments; the SOHO (Solar and Heliospheric Observatory) mission was initially proposed to combine the properties of GRIST with the study of the extended corona (up to several radii of heliocentric distance) by observing the scattered Ly-alpha and OVI radiation, which was also the basis of the SCE (Solar Corona Explorer) mission proposal; the development of the interest about the variability of the Sun, both in itself and for its consequences in the history of the Earth, led to propose observations of the solar constant (included in DISCO).
Measurements of Absolute Collisional Cross Sections at Harvard-Smithsonian CfA
Authors: Kohl J.L. , Deutsch L.K. , Gardner L.D. , Lafyatis G.P. , Young A.R.
Published: July 2016

The major goal of this research program is to determine, experimentally, accurate absolute cross sections for dielectronic recombination (DR) in multiply and singly charged atomic ions. Our initial measurements of DR in C3+ are designed to provide a “bench mark” cross section for a simple atomic system. The experiment determines energy averaged DR cross sections for a well defined process involving a specific stabilizing transition. The fields in the region where dielectronic recombination occurs can be made small (≅ 0.25 V/cm) in order to minimize the effect of Stark mixing which is expected to enhance the DR process. We are presently adding the capability to apply known mixing fields up to 5 V/cm in the electron-ion interaction region of our apparatus.
Critical Compilations of Atomic Transition Probabilities
Authors: Martin G.A. , Fuhr J.R. , Wiese W.L.
Published: July 2016

The NBS Data Center on Atomic Transition Probabilities is nearing completion of a critical compilation of atomic transition probability data on allowed and forbidden transitions in the elements scandium through nickel in all stages of ionization. This compilation constitutes a revision of a series of smaller NBS compilations published in recent years in the Journal of Physical and Chemical Reference Data. Upon completion of this project, work on updating of an even earlier compilation covering the elements hydrogen through neon will be initiated.

The world literature on atomic transition probabilities is collected and catalogued on an ongoing basis by the Data Center. A master reference list is maintained, and annotated bibliographies are issued as the number of new articles in the literature and the resources of the Center permit. A computerized bibliographic database system is being developed to enhance the capability for handling bibliographical information in the NBS data centers on transition probabilities, line shapes and shifts, and energy levels. Development of a computerized database of critically evaluated numerical data on atomic spectroscopic quantities is planned for the future.
3s – 3p and 3p – 3d Transitions in Neon-Like Ions of the Iron Group Elements
Authors: Litzén U. , Jupén C.
Published: July 2016

The spectra of highly ionized scandium, titanium, vanadium and chromium emitted from laser-produced plasmas have been recorded in the region 270–600 Å. The radiation from a Quantel NG24 Nd:YAG/glass laser giving the maximum energy 4J in 3ns pulses was focused on plane metal targets. The target was placed at the Sirk’s focus of a 3-m normal incidence spectrograph with the target surface parallel to the slit. The laser beam was perpendicular to the target and to the entrance axis of the spectrograph. By this arrangement the spectral lines from different ionization stages differ in length, the highest states giving the shortest lines. Well-determined lines from spark recordings of sodium-, magnesium-, aluminium-, and silicon-like ions were used for the wavelength determinations.
X-Ray Spectroscopy to Determine Line Coincidences Between K- and L-Shell Transitions
Authors: Burkhalter P.G. , Newman D. , Gilfrich J.V. , Brown D.B. , Rockett P.D. , Charatis G. , Hailey C. , Matthews D.L. , MacGowan B.
Published: July 2016

Accurate wavelengths for highly-ionized L-shell spectra were measured in the 10–16Å region. The purpose being to determine lines in coincidence with L-shell transitions from the elements oxygen, fluorine, and neon. L-shell transitions have been proposed for resonant photopumping of K-shell electrons in these elements to, generate lasing between upper levels in the 40–150 eV region. The current effort improves on and expands the earlier spectroscopic work performed at KMS Fusion, Inc., where possible line coincidences were identified for photoionizing in the 1–3 and 1–4 levels in fluorine. New experimental techniques have led to a wavelength accuracy now believed to be ± 2 mÅ for cases in which adequate calibration lines are available. Exact spectral line matches were found for Mn with the F H,-line at 12.643Å and for both Mn and Cr with the F He line at 14.458Å. The Mn line at 12.643Å has been identified, using ab initio atomic structure calculations, as the 1D2 − 1F3 transition in Be-like Mn XXII. The Mn line emissivity was determined to be 30 MW into 2 steradians for a conversion efficiency of 0.04%. Photopumping with Mn coated gasfilled targets is presently being tried in gain measurement experiments at LLNL.
Dielectronic Recombination of Highly Stripped Argon Ions: Theoretical Calculations and Direct Observations in an Ebis Source
Authors: Loulergue M. , Dubau J. , Briand J.P. , Charles P. , Laurent H.
Published: July 2016

The dielectronic recombination is one of the most important atomic processes in highly ionised plasmas. It corresponds to the simultaneous capture of a free electron and excitation of an ion, i.e.

It is a collisionally resonant process which occurs only at the energy of the corresponding autoionisation electron. We present here a preliminary theoretical analysis of the results of an experiment using a novel technique in which it is possible to observe the interaction of a given ion with an electron at a given energy and so to measure the differential dielectronic cross section corresponding to each resonant level of this ion.
New Methods in Development of X-Ray Optics for Plasma Diagnostics of Laser - Produced Plasma
Authors: Hudec R. , Valníček B.
Published: July 2016

A new technology was developed for manufacturing of precise and low-cost X-ray grazing incidence microscopic optics.

Imaging experiments represent one of the main directions in the Czechoslovak X-ray astronomy program. The Space Research Department of the Astronomical Institute of the Czechoslovak Academy of Sciences in Ondřejov has been active in the development of X-ray mirrors since 1970. We have participated in 7 space X-ray imaging experiments. 6 experiments were flown onboard the Vertical 8, 9 and 11 rockets in the years 1979, 1981 and 1983 (Hudec et al. 1984a), one experiment was flown onboard the Soviet orbital station Salyut 7 in the year 1982 (Valníček et al. 1983 and Hudec et al. 1984b). The experiments represent both small solar X-ray imaging telescopes and big stellar X-ray telescope.
Radiatively-Driven Stellar Winds
Authors: Lucy L.B.
Published: July 2016

In this review, attention will be focussed exclusively on the winds of hot stars, concentrating for the most part on spectral types 0 and B. For these stars, a clear consensus has emerged that it is the gradient of selective radiation pressure - i.e., line-driving - that explains the high terminal velocities, typically ~ 2000 km s−1, of their winds. Accordingly, few would now doubt that the supersonic zones of these winds present us with rather clean examples of line-driven flow, whose investigation therefore properly belongs under the heading “Radiation Hydrodynamics”. Moreover, in marked contrast with other astronomical environments where line-driven winds may exist, the stellar case is geometrically and parametrically well defined and is thus by far the best natural example from which to learn about such flows.
Neutrino Transport in a Type II Supernova Environment
Authors: Schinder Paul J. , Shapiro Stuart L.
Published: July 2016

We discuss the full problem of neutrino transport in the context of a Type II supernova environment. We describe the “standard model” of Type II supernova, which involves the core collapse and core bounce of an 8 — 20M⊙ star. Although the shock produced in the standard model is supposed to expel the outer layers of the star, this does not happen in the best numerical collapse calculations without considerable numerical tweaking, if at all. In this model, neutrino transport plays an important role. We describe the weakness of the best transport approximation currently used in collapse calculations, the flux-limited diffusion approximation. We investigate the effect of a full transport approach by constructing two different types of model atmospheres, with conditions chosen to closely approximate conditions found in full collapse calculations. The first model is to construct equilibrium plane-parallel hydrostatic neutrino atmospheres. The second is to solve the equations of neutrino hydrodynamics for a spherical shell of matter, with a piston and a source of neutrinos at the lower boundary. We describe in detail the neutrino interactions which are important in the supernova problem. We present the equations of neutrino hydrodynamics and neutrino hydrostatics which are solved in the two models, and emphasize the differences between photon transport and neutrino transport. We describe briefly a “toy” model, the neutrino Eddington atmosphere, which highlights the differences between photon and neutrino atmospheres. We present the results of our model atmosphere calculations for a few selected cases of interest. Finally, we summarize alternatives and extensions to the standard model which are of current interest and may hold the answer to the Type II supernova problem. However, the delicate balance between competing effects suggest that a rigorous calculation of neutrino transport will be required to obtain a definitive answer.
Observations of Compact X-Ray Sources
Authors: Tanaka Y.
Published: July 2016

This paper reviews the present status of observations of compact X-ray sources with emphasis on the aspects related to radiation hydrodynamics, based on the recent observational results, in particular those from the Japanese X-ray astronomy satellite Tenma. The main feature of Tenma is a large-area gas scintillation proportional counters (GSPC) with energy resolution twice that of ordinary proportional counters, which can yield information on energy spectrum superior in quality to previous results. We shall deal here only with those galactic X-ray sources in which the compact object is a neutron star or possibly a black hole, and exclude white dwarf sources.

There exist more than one hundred bright X-ray sources in our galaxy in the luminosity range 1036−1038 ergs/sec. They are most probably binaries involving a neutron star or, in some cases, possibly a black hole. The high luminosities of these sources are explained in terms of the large gravitaional energy release by matter accreting from the companion star to the compact object.
Radiation Hydrodynamics of the Broad Line Region in Seyfert Galaxies and Quasars
Authors: Mathews William G.
Published: July 2016

The broad line region in quasars and in the nuclei of active galaxies is the site of remarkable hydrodynamic activity unprecedented elsewhere in the universe. Considerable theoretical effort has been directed to determine how this intense radiation is related to high velocity gas motions in these small regions, which, because of their great distances, cannot be resolved by direct observation. A better theoretical understanding of the nature of the broad line-emitting gas involves many novel aspects of radiation hydrodynamics and may eventually provide insights into the nature of the mysterious quasar phenomenon itself.

Continuum and emission line properties of active galaxies and quasars are sufficiently similar that there is little doubt that both can be accounted for by a similar or closely related physical model. The main difference is one of luminosity; typical quasars are considerably brighter than Seyfert galaxies.

In the discussion below the relevant observations of quasars and active galaxies are briefly reviewed with an emphasis on the physical properties of the line-emitting gas and its immediate environment. Arguments that support the importance of radiation forces in producing the observed gas velocities are summarized. Finally, the nature of the acceleration process is described with particular attention paid to the various instabilities that may be present and which are generally characteristic of situations in which plasma velocities result directly from the deposition of radiative momentum. In fact, these troublesome instabilities suggest that radiative forces, although very strong, may provide only a partial explanation of the gasdynamical activity observed.
The Teaching of Astronomy at University Level in Portugal
Authors: Lago M.T.V.T.
Published: July 2016

In 1984, the University of Porto started a program for the first degree in astronomy in a Portuguese university. Jointly offered by the Physics and Applied Mathematics Departments at the School of Sciences, the degree is strongly marked by the interdisciplinary character essential for the teaching of modern astronomy. It includes 37 per cent in physics, 32 per cent in mathematics, 25 per cent in astronomy, and 6 per cent in chemistry, geology, mathematics, or physics. Its structure in course units comprises:
Multiple-Choice Questions
Authors: Bishop Roy L.
Published: July 2016

Although few people enjoy tests and examinations, these aspects of education appear to be essential to the maintenance of standards, and they provide a vital learning environment for both students and instructor. Opinions regarding “objective,” or “multiple-choice,” questions range from very positive, which is my own qualified opinion, to very negative. In the latter instance, some claim that such questions should never be used, and refer derisively to multiple-choice questions as “multiple-guess questions.”
A Correspondence Course in Astronomy
Authors: Zeilik Michael
Published: July 2016

As do most universities in the United States, the University of New Mexico (UNM) offers a one-semester introductory course in astronomy aimed at the vast audience of non-science majors. UNM is a non-selective, minimally-funded state research university with an undergraduate enrollment of about 20,000 students — with a median age of 26. Many of the students have jobs and families and attend on a part-time basis. The Physics and Astronomy Department usually offers three sections of Astronomy 101 to accommodate students’ schedules: in the morning, afternoon, and evening. Total enrollments per semester range between 400 to 600; the course is also regularly taught during the summer. The class has no prerequisites of any kind, is advertised as “non-mathematical,” and does not have a required lab for observations. (A related lab course, Astronomy 111, is available, and is taken by about 100 students per semester.) The course attempts to cover “all” of astronomy with a special emphasis on the theme of cosmic evolution. Instructors tend to use visual aids (slides, videos, films, laser disks, and microcomputers) heavily. Students usually rate the instructors and the course in the top 10 to 30% of all instructors who choose to use a university-wide class evaluation instrument, compared to a group of other lower-division courses.
Cratering in the Classroom
Authors: Bisard Walter
Published: July 2016

The SEMS Project (Science Education in Middle School) in Michigan is a cooperative science education improvement effort by several universities, hundreds of school districts, and the state department of education. Upper elementary and middle/junior high school teachers have been targeted for improvement of science instruction. Although the initial area of focus included teachers of grades five through nine, the project has been successfully extended to early elementary grades. While there are many excellent teachers at these grade levels, research findings indicate that 49 per cent of all middle school science teachers are teaching without a major or minor in science! The situation is even more critical at the upper elementary levels.
Dynamic Human (Astronomical) Models
Authors: Bishop Jeanne E.
Published: July 2016

Many educators have found that models can add a lot to the understanding of astronomical concepts. Attractive commercial models of the solar system and celestial globes are readily available. Many models can be constructed of common materials — I found in my doctoral dissertation work that models made and manipulated by students increased retention of concepts of the celestial sphere and rotation, the seasons, lunar phases, and planet motions.

But there is another type of model which I have found very successful. I call it the “dynamic human model.” Actually, the concept is not new. I know that many good teachers have a favorite demonstration in which one or more students represent the Earth, sun, or moon. Also, the Elementary-School Science Project of the University of Illinois contained activities for student models to distinguish between Ptolemaic and Copernican systems. However, I do not think the idea has been extended as far as it should be. I would like to suggest ideas for dynamic human models beyond what I have seen elsewhere.
The Universe in the Classroom: A Newsletter on Astronomy for Teachers
Authors: Fraknoi Andrew
Published: July 2016

Since 1984, the Astronomical Society of the Pacific (ASP) has sponsored a quarterly newsletter on teaching astronomy in grades 3-12. Cosponsored by the American Astronomical Society, the Canadian Astronomical Society, and the International Planetarium Society, the project now reaches over 20,000 teachers and schools in the US and Canada.

We would like colleagues overseas to examine the newsletter, and, if they find it useful, to consider translating and distributing it. We will be glad to make it available without charge to anyone who is interested.

Since 1978, the summer meetings of the ASP — held in a different city each year — have featured one to three days set aside for workshops on astronomy for teachers. In recent years, between 150 and 200 teachers have come each summer— at their own expense — to take these credit workshops and learn more about astronomical topics, activities, and resources.
A Science and Mathematics Teaching Center
Authors: Bisard Walter
Published: July 2016

It is widely known that a crisis in science and mathematics teaching exists in the United States. This crisis has reached all levels of education, from elementary to secondary to colleges and universities. The problem, which is easy to define but difficult to resolve, is trifold: there are not enough high-quality science and mathematics teachers; present teachers are teaching out-of field or are out-of-date and in need of subject updating; and the average education graduate is only minimally qualified to teach science and math. These factors have caused national and state “alarms” to be published that point out the increasing mediocrity and an overall lack of science education in our nation’s schools.

Central Michigan University, long among the nation’s leaders in the training of teachers at all levels, is taking steps to remedy this alarming situation. A Science and Mathematics Teaching Center, designed to confront the problem head-on, has been founded. The Center’s major purpose is to improve the quality of science and math teaching. This goal is being accomplished through a series of workshops, seminars, in-service programs, conferences, and teacher outreach programs.
The Mills Public Observatory in Dundee
Authors: Vincent Fiona
Published: July 2016

The only full-time public observatory in Britain is the Mills Observatory in Dundee, Scotland. John Mills was a successful businessman in Victorian Dundee with an interest in astronomy. He bequeathed his money to build a public astronomical observatory in the city, for studying “the wonder and beauty of the works of God in creation.” The Mills Observatory was eventually opened in 1935.

Dundee is situated on the northern shore of the River Tay, in central Scotland. The Observatory stands on a wooded hill (an extinct volcano) near the center of the city. The trees shelter it from virtually all direct city light, while leaving an uninterrupted view south across the Firth of Tay. There is some scattered light, but in clear weather the sky can be surprisingly dark, and the Milky Way distinctly visible.
Introductory Astronomy for Mature Students
Authors: Waller William H.
Published: July 2016

Much of this meeting has been concerned with the teaching of introductory astronomy to children, teenagers, and young adults. Introductory astronomy for working and retired adults has been given short shrift, however. Because the mature population is significant in number and in its influence on governmental support for astronomy, I thought that some mention should be made. My own experience concerns the educational programs that are available to mature students in the United States.

Most working adults are restricted by their jobs to taking classes in the evening. Most large universities in the United States provide such classes. These are often administered by organizations that are completely autonomous from the “host” school. A typical arrangement is for the school to provide classroom space, access to audio-visual equipment (sometimes), and university credit for those who register for credit. The “adult education,” “continuing education,” or “university extension” organization handles the rest. It obtains the necessary faculty to teach the courses, advertises the classes, and administers the registration and grading. For the “credit” courses in astronomy, the most common teachers are graduate students and postdoctoral fellows looking for some extra cash and teaching experience. There is no real impetus for regular faculty members to teach these classes. This is an unfortunate circumstance that could be remedied by some private, state, or federal funding of endowed “chairs” in adult education.
Using Teleconferencing for A Planetarium Lesson
Authors: Wasiluk Elizabeth S.
Published: July 2016

Before coming to West Virginia, I worked for Delaware-Chenango BOCES as their telelearning coordinator. BOCES stands for “Board of Cooperative Educational Services.” Such organizations exist throughout New York State for the purpose of pooling resources of school systems and providing services and equipment they might be unable to afford on their own. Examples of the services they provide include distance learning, vocational education, computer services, etc. Our BOCES owned a portable Starlab planetarium for loan to member school districts.

Carol Kwiencinski, from Downsville Central School in Downsville, New York, used the portable planetarium with her students. Her students asked her many questions she could not answer, particularly about black holes. As an add-on to her planetarium session, she approached me to do a teleconference with a planetarium director, Mitch Luman of the Koch Planetarium and Science Center, Evansville, Indiana. To set up the conference, we used a speakerphone, which is basically a set of amplifiers and microphones that allow students to speak and listen to a telephone conversation as a group.
Teaching of Astronomy in India: With Special Reference to Teaching of Astronomy at Lucknow University
Authors: Saxena P.P.
Published: July 2016

Modern astronomy started in India when an astronomical observatory was founded in Madras as early as 1786 by the East India Company and to which the Indian Institute of Astrophysics traces its origin. There are, however, records of astronomical observations taken through a telescope from Pondicherry that elucidate the double-star nature of Alpha-Centauri as early as in 1689. Since then many more research centers in astronomy have been established. Today, institutions like the Indian Institute of Astrophysics (Bangalore), the Raman Research Institute (Bangalore), the Center of Advanced Study in Astronomy (Hyderabad), the Tata Institute of Fundamental Research (Bombay), and the Physical Research Laboratory (Ahmedabad) are engaged in pioneering work in theoretical and observational branches of astronomy and astrophysics.
Two Centuries of Study of Algol Systems
Authors: Batten Alan H.
Published: July 2016

The periodicity of the light variation of Algol, discovered just over 200 years ago, may be regarded as the beginning of the study of eclipsing binary systems, especially those of the Algol type. Such studies, however, gained no real momentum until Vogel, 100 years ago, demonstrated by spectroscopy that the binary hypothesis of Algol’s light changes is, in its essentials, correct. Three elements were needed to give us our modern notions of evolution by mass-transfer, namely: (i) results of combined analysis of light-curves and velocity-curves, (ii) evidence of circumstellar matter within binary systems and (iii) the notion that at least one component of an Algol system was near the limit of dynamical stability. All three entered the literature within about a decade, approximately halfway through the second century of eclipsing-binary studies; but it is the computational and instrumental developments of the last 25 years that have made real progress possible. We still lack commensurate theoretical developments, and the whole question of the contribution of Algol systems to the development of the Galaxy has barely been considered.
Time-Resolved Spectroscopy of Accretion Disks in Algols
Authors: Kaitchuck Ronald H.
Published: July 2016

Time-resolved spectroscopy during the eclipse of short-period Algol systems, has shown their accretion disks to be small, turbulent structures with non-Keplerian velocity fields and asymmetries between the leading and trailing sides of the disk. These transient disks are produced by the impact of the gas stream on the mass-gaining star, and occur in systems where the star is just large enough to ensure the stream collision is complete. These emission line disks and the excess continuum emission do not always occur together. The permanent accretion disks in at least a few of the long-period Algol systems have features in common with the transient disks including non-Keplerian velocity fields.
Polarizing Gas at Small Optical Depths Around Algols
Authors: Koch R. H. , Elias N. M. , Corcoran M. F. , Holenstein B. D.
Published: July 2016

The origins of visible-band linear polarimetry of Algols and objects related to them are reviewed. It is pointed out, not for the first time, that the polarization signals of these systems can vary sporadically by significant amounts. The difficulty of evaluating the interstellar component of the observed polarization is discussed and these components are evaluated anew for each object studied in this paper. With one possible exception, the polarization signals intrinsic to these binaries derive from electron scattering. A well-defined model is applied to the constant and variable (but phase-locked) polarization signals. Limits to the mass associated with a scattering disk in each binary are derived. Within broad limits, concentrations of scattering mass within and above or below the orbital plane are also developed as are the centroid longitudes of these concentrations within the system. It is pointed out that very few measures of visible-band, circular polarization have been made but that cm-wavelength measures of Algol itself have been very informative.