bluuebunny/crossref_metadata_2025 huggingface dataset:
RR Lyrae AND BL Herculis Variables
Authors: Cox Arthur N.
Published: July 2016

The RR Lyrae variables are currently believed to have masses between about 0.5 and 0.8 M⊙, effective surface temperatures between 6350 and 7500K, radii from about 4.0 to 6.0 R⊙ and luminosities between log L/L⊙ of 1.5 and 2.0. Since they are found in population II locations, they generally have Y = 0.3 and Z = 10−3 , but there are exceptions for both higher Z like the sun and lower Z like 0.0002. In globular clusters the periods range from 0.25 - 0.45 day for the first overtone pulsators and 0.40 - 0.80 day for those in the fundamental mode, depending on their luminosity. At transition lines, to be discussed in detail below, the switch from fundamental to first overtone, or maybe vice versa, involves a period change factor of about 0.74 - 0.75.
Low-Mass Evolution from He Ignition to Beyond the Horizontal Branch
Authors: Despain Keith
Published: July 2016

The evolution of an 0.6 M⊙ stellar model during core helium burning is presented. Following the off-center ignition of helium in the “core” flash, the star remains on the red giant branch for > 106 years, undergoing twelve additional flashes. After leaving the giant branch, the star evolves on the horizontal branch for 8.15×107 years before returning to the giant branch and undergoing strong helium-shell flashes. The implications for horizontal branch and RR Lyrae stars are discussed.
The Absolute Magnitudes of RR Lyrae Stars
Authors: Manduca A. , Bell R. A.
Published: July 2016

A theoretical counterpart to the Barnes-Evans relation between stellar surface brightness and V-R color has been calculated from model atmospheres for parameters appropriate to RR Lyrae stars. Such a relation can be used to derive stellar angular diameters from V,R photometry and, when applied to variable stars and combined with a radial velocity curve,, to derive radii, distances, and absolute magnitudes by the method of Barnes et al. (1977, MNRAS,178, 661). This was done for RR Lyr and X Ari using the photometry of Moffett and Barnes (1980, private communication) and radial velocities from the literature. The resulting absolute magnitudes are  ± + 0.59 + 0.25 for X Ari and  = 0.61 + 0.35 for RR Lyr. The method is shown to be a very accurate way of determining radii, distances, and absolute magnitudes for RR Lyrae stars which compares very favorably to the variations of the Baade-Wesselink technique currently in use.
Blazhko Effect in the RR Lyrae Variables as a Result of Double Mode Pulsation
Authors: Borkowski K.J.
Published: July 2016

On the basis of a frequency analysis of light variations of AR Her a double-mode pulsation is proposed as an explanation of the Blazhko effect. The analysis revealed a number of components, which can all be interpreted as a result of nonlinear superposition of the fundamental mode, and a mode with period P = 1/(2/P0 + 1/PB) ~ P0/2, where P0 = 0d.470 and Pb = 31d.55 denote the fundamental and the Blazhko effect periods, respectively.

The P ⋍ P0/2 mode can be identified as the second or the third radial overtone. In both these cases the “beat” masses derived from a comparison of the calculated (nonadiabatic) and observed period ratios for RR Lyrae variables with Blazhko effect are different from their evolutionary masses.
Pulsations of the R Coronae Borealis Stars
Authors: Cox J. P. , King D. S. , Cox A. N. , Wheeler J. C. , Hansen C. J. , Hodson S. W.
Published: July 2016

The radial pulsations of very luminous, low-mass models (L/M ˜ 104, solar units), which are possible representatives of the R CrB stars, have been examined. These pulsations are extremely nonadia–batic. We find that there are in some cases at least one extra (“strange”) mode which makes interpretation difficult. The blue instability edges are also peculiar, in that there is an abrupt excursion of the blue edge to the blue for L/M sufficiently large. The range of periods of the model encompasses observed periods of the Cepheid-like pulsations of actual R CrB stars.
Hydrodynamic Studies of the Nova Outburst
Authors: Starrfield S.
Published: July 2016

Over the past few years, significant advances have been made in our understanding of the nova outburst. The theoretical studies have shown not only that a thermonuclear runaway in the envelope of a white dwarf reproduces the gross features of the nova outburst (c.f.; Starrfield, Sparks, and Truran 1978, Sparks, Starrfield, and Truran, 1978, Gallagher and Starrfield 1978), but also made important predictions regarding the observed behavior of the outburst itself. The observational studies have provided us with new data concerning the evolution of the bolometric light curve of a nova during outburst, the elemental abundances in the ejecta, the formation of dust during the outburst, and the structure of nova binaries (c.f., Gallagher and Starrfield 1978).
William Herschel, Bath, and the Philosophical Society
Authors: Porter Roy
Published: July 2016

Richard Brinsley Sheridan, a Bathonian, opens his comedy,The Rivals, with a social sneer. Fag, the stylish apostle ofbon ton, meets his fellow servant Thomas, a clodhopping yokel, and exclaims: “Why Thomas … But who the deuce thought of seeingyouin Bath?”. One might ask the same of William Herschel, the Hanoverian bandsman’s son, who, having discovered Uranus, was to pass the last forty years of his life as a Crown pensionary, living just outside Windsor. How did Herschel come to spend his formative scientific years in Bath, resort of the giddy and the gay? How did he come to discover Uranus there?
The Pre-Discovery Observations of Uranus
Authors: Forbes Eric G.
Published: July 2016

In hisAstronomisches Jahrbuchfor 1784, Johann Elert Bode summarises the scanty information that had reached Berlin concerning the recent discovery on 13 March 1781 of a new heavenly body by a still-unidentified observer in England. Its easterly progress through the Milky Way during the interim six months had been parallel to the ecliptic, and thus entirely consistent with the view - hitherto based only upon its brightness and clearly-defined disc - that it was a planet and not a comet. Bode therefore asks why this sixth-magnitude object had not been previously detected, and raises the question of whether it had in fact been observed by earlier astronomers but misidentified as a star. He himself had already scanned the star-catalogues of Tycho Brahe, Johann Hevelius, John Flamsteed, and Tobias Mayer; and had come to suspect that a missing sixth magnitude star in the constellation Capricorn, observed by Tycho on 20 November 1589, might have been the planet. A second possibility which still required investigation was Mayer’s star No. 964, observed in Aquarius on 25 September 1756.
Internal Structure of Uranus
Authors: MacFarlane J. J. , Hubbard W. B.
Published: July 2016

We present an updated study of Uranus interior models using current information about the planet’s gravity field and rotation rate. The most plausible model, both from the point of view of recent data and cosmogony, has a central core of iron and magnesium silicates, an outer envelope of liquid water, methane, and ammonia, and a deep “atmosphere” of almost four earth masses of hydrogen, helium, and methane. The “atmosphere” contains a gravit at ionally nonnegligible amount of methane — about 40% by mass. All plausible models are most consistent with a rotation period of ~15 to 16 hours.
Data on Time and Polar Motion: Immediate Accessibility
Authors: McCarthy Dennis D. , Westerhout Gart
Published: July 2016

Users of time and polar motion information have requirements for data which are somewhat different from those usually considered for astronomical data files. Because of these requirements, it is necessary to provide immediate access to the latest information on Earth orientation and even predictions of future orientation. For other applications where data of the highest accuracy is required with little concern for the delay between observations and the determination o f the required information, a more traditional approach may be used. To meet all of these needs a versatile automated data retrieval system is demanded. The U. S. Naval observatory is now implementinq such a system in the area of Earth orientation information and for precise time and time interval applications. Data are available through a series of weekly, monthly, and annual reports, as well as through a digital communications link to Time Service machine-readable files.
The International URSIGRAM and World Days Service
Authors: Simon P.A
Published: July 2016

Broad outlines of a permanent service involved in the prompt dissemenition of solar and geophysical data.

The Solar Activity has an effect on several modern technics. For instance, during a transient increase of solar UV flux, the trajectory of a low perigee satellite can slightly change, a ionospheric communication link can fade out or some scientific program can only be carried out during some outburst of the solar activity.
System software approaches to the Analysis of Multidimensional Data Structures
Authors: Albrecht Rudolf
Published: July 2016

In this review paper on software techniques, the concepts of “software system” and “data base interface” are defined in the context of astronomical data analysis requirements. Principles of software desiqn and maintainance over are discussed.

A deliberate effort was made to stay as close as possible to the astronomical application and not deviate too much into computer science.
Prospects for automated solution of the subject characterization problem in the bibliographic services
Authors: Schiminovich S.
Published: July 2016

Evidence is presented on the feasibility of an automated generation of classification schemes and the subsequent indexing of papers with the automatically generated subject headings. The output generated for Astronomy and Astrophysics compares favorably with the schemes used by the services and is not inconsistent with recently proposed classifications. Implementation of the automatic techniques seems not only feasible but desirable. However, it would require that the services include for each paper in their database its citations to other papers.
Astronomy and Astrophysics Abstracts : a status report
Authors: Schmadel L.D.
Published: July 2016

The astronomical bibliography ‘Astronomy and Astrophysics Abstracts’ (AAA) is the direct successor of the well-known ‘Astronomischer Jahresbericht’ (AJB). AAA is now going into its 13th year of existence. It is the aim of this contribution to outline the present status and the future plans of the abstracting and indexing work at the Rechen-Institut.
The Bibliographical Star Index
Authors: Ochsenbein F.
Published: July 2016

The Bibliographical Star Index (B.S.I.) ries to solve the problem of retrieving the observations or any kind of notes about a star. This file was initiated by Prof. R. Cayrel in 1964 and is going on through a collaboration between Paris-Meudon Observatories and the Stellar Data Center (see Ochsenbein and Spite, 1977). In pratice, the astrophysical papers published on stars are read, the names of all the stars cited in each paper are recorded; simultaneously, the complete bibliographical reference is recorded : name of the author(s), journal, volume, page, year of publication and the full title. These data are keypunched and stored in the computer, each star name is then tested, frequently replaced by a more used designation, and entered into the B.S.I. The retrieval program than lists all the papers with authors, references and full title in which a given star is cited.
Copyright and use of computers for access to protected works
Authors: Guerassimov Evgueni
Published: July 2016

It is considered that the term “copyright” originated in Anglo-Saxon law at the beginning of the eighteenth century. Originally, it meant a “right to make a copy” of a work. This was because at that time copying (mainly by printing presses) was almost the only mode of reproduction.
The UK Schmidt telescope plate catalogue and problems associated with increasing numbers of plates and users
Authors: Tritton S.B.
Published: July 2016

The UK 1.2m Schmidt Telescope (an outstation of the Royal Observatory Edinburgh) is situated at Siding Spring Observatory in New South Wales, Australia. The telescope has been operational since 1973 and has, to date, taken about 7000 plates. This paper discusses some of the problems associated with cataloguing these plates and keeping track of their locations.
The “Catalogue of Stellar Groups”: A Progress Report
Authors: Egret D. , Jaschek M.
Published: July 2016

The catalog will provide lists of stars for about fifthy groups of determined spectral peculiarity. The adopted selection procedure, the connection to the C.D.S. data base and the future developments are described.
Data retrieval in the metacatalogue of galaxies
Authors: Kalinkov M. , Kuneva I. , Stavrev K.
Published: July 2016

To study the large scale structure of the Universe, we started several years ago the compilation of a new type of catalogue – a metacatalogue of optical extragalactic objects, on magnetic tape. This catalogue may be regarded to some extent as a data bank but it will also include characteristics, reduced to homogeneous systems. The Metacatalogue will contain information for galaxies, clusters of galaxies, counts of galaxies and bibliographical data. Until now some files for individual catalogues and lists have been created, which may be used also before their merging into the Metacatalogue.
Improved Coude Efficiency of Existing Telescopes
Authors: Grundmann W.A. , Richardson E.H.
Published: July 2016

The ordinary coudé train has a single, large, aluminum coated mirror at each reflection point. This introduces considerable light loss because several reflections are required, and the long light path in turbulent air blurs the stellar image by telescope “seeing” effects. The transmission can be increased and the blur decreased by a train of small mirrors with high reflectance coatings. The high reflectance coatings have the added advantages that they can reduce polarization effects and flatten response curves.
Use of Large Telescopes in Fast Focal Ratio Mode – Application to the 6m Telescope (BTA)
Authors: Courtes G. , Boulesteix J. , Sivan J.P. , Petit H. , Karachentsev I.
Published: July 2016

Large aperture telescopes usually have an unavoidably long focal length so that stellar image diameters are often much larger than the resolution of the detector. The detection of extended sources can take advantage of a faster focal ratio and both stellar and extended monochromatic sources can be detected with great sensitivity by using interference filters and a focal reducer, without much loss in resolution. Extragalactic results obtained with the 6 meter telescope at focal ratio f/1 are given as examples.
Information Efficiencies of Telescopes and their Instrumentation
Authors: Rylov V.S.
Published: July 2016

A criterion based upon information content allows one to obtain objective estimates of the efficiencies of astronomical observations for the whole system of light receiving and recording equipment, including the conditions of observation. The proposed method for calculating this information efficiency relies on the analysis of the output observational material and not on the characteristics of optical and electronic components of the instrumentation. The method is quite simple to use for comparison of different astronomical observations and instrumentation (Rylov, 1977, 1979; Karapetian and Oskanian, 1978).
The 200-Channel Spectrometer of the Crimean Astrophysical Observatory
Authors: Abramenko A.N. , Alexandrin Ju.S. , Prokof'eva V.V. , Yakushin V.N.
Published: July 2016

A simple, low cost, television spectrometer has been constructed at the Crimean Astrophysical Observatory using an I-Isocon image tube for analog-digital recording of stellar spectra. High quantum efficiency (0.04) together with good accuracy (±0.3%) and repeatability are obtained.
Speckle Interferometry with the BTA Telescope
Authors: Dudinov V.N. , Konichek V.V. , Kuz'menkov S.G. , Tsvetkova V.S. , Rylov V.S. , Gyavgyanen L.V. , Erokhin V.N.
Published: July 2016

The description of a speckle camera used with the BTA 6-meter telescope is given. Observational data recorded on photographic film are processed with a Fourier optical spectrum analyzer. Results of binary star measurements are presented. Analysis of short exposure images of a point source obtained with telescopes of various sizes allows the estimation of atmospheric parameters which are necessary for correct application of speckle interferometry.
Experiments in Differential Speckle Interferometry
Authors: Beckers Jacques M. , Hege E. Keith
Published: July 2016

We propose to develop a technique to achieve submillisecond of arc resolution on stellar objects. It uses the fact that the spectrum of the light emitted by such an object often changes across its surface either because of Doppler shifts, Zeeman splitting, abundance anomalies or changes in the stellar atmosphere. By an appropriately designed experiment using narrow band (0.5 – 1 Å) filters, it is then possible to obtain differences between the position of speckles in the stellar image when viewed in slightly different wavelengths. It is possible to determine these differences in the position of the speckles with an accuracy much higher than the speckle size itself using techniques which are already developed for binary star-speckle research. We propose to use the technique of “Differential Speckle Interferometry” to study stellar rotation, evolution of stellar systems, spectroscopic binaries, the mass-luminosity relation, and peculiar A stars.
Two Dimensional Interferometric Photon Counting Observations with the 6m Telescope
Authors: Boulesteix J. , Georgelin Y. , Marcelin M. , Fort J.A.
Published: July 2016

This detector has been in use since 1977. Following Labeyrie (1977), it consists of a microchannel plate electrostatically focussed intensifier (TH 9304) coupled by fiber optics to an SIT camera (TH 9655), these parts being manufactured by THOMSON-CSF (FRANCE). The diameter of the S20 photocathode is 25mm but the silicon target is only 18mm wide. The scanning electronics are conventional. The detector is cooled to -5°C, the photocathode being in a dry nitrogen chamber. The system has been described by Boulesteix (1978).
Measurements of Photon Statistics with Nanosecond Resolution
Authors: Dravins Dainis
Published: July 2016

A photon-counting astronomical instrument for optical observations with nanosecond time resolution is being developed to observe the statistical distribution of photons in time. The purpose of this ‘quantum-optical spectrometer’ is to measure quantum-statistical properties of the photon gas and to study the physics of radiative deexcitation. The amount of photon bunching in time contains information on parameters such as the fraction of stimulated emission and the degree of frequency redistribution that the light has undergone.
Utilisation des Recepteurs Electronographiques avec les Grands Telescopes
Authors: Wlerick G. , Duchesne M. , Servan B. , Gex F. , Munier J.M.
Published: July 2016

La France a toujours montré un intérêt particulier pour l'électronographie. Ceci est dû, d'une part au travail de pionnier d'André LALLEMAND (1904-1978), d'autre part au fait que les cameras électroniques sont bien adaptées aux observations astronomiques, en particulier, avec les grands télescopes.
Molecular clouds: comet factories?
Authors: Clube S.V.M.
Published: July 2016

Recent discoveries seem to indicate a catastrophic history of terrestrial evolution, explicable in terms of Oort cloud disturbance by molecular clouds in the Galactic disc. The problem of Oort cloud replenishment thus assumes considerable significance and reasons are given for supposing comet exchange takes place during actual penetration of molecular clouds. The number density of comets in molecular clouds, thereby implied, seems to suggest primary condensations of ≤103km in a dense precursor state of spiral arms. If chemical and/or isotopic signatures of comets should indicate an extra-Solar System source, the theory of terrestrial catastrophism may place new constraints on our understanding of the origin of molecular clouds.
Empirical data from Oort’s cloud
Authors: Delsemme A.H.
Published: July 2016

Empirical evidence about the size and the origin of the Oort’s cloud of comets is confronted with theories about its origin. The slow diffusion of the orbits of the “new” comets into the inner solar system implies a redefinition of the concept of “new” comet. A gradual transfer of orbital angular momentum occurs from the planets to the comets as the comets grow older on shorter period orbits. The observed retrograde to prograde ratio of the new comets is difficult to explain. Either it comes from a poorly understood observational bias, or from a neglected secular action of the Galaxy, or it implies a recent asymmetrical perturbation of the Oort’s cloud (less than 10−20 million years ago). The grazing incidence of a giant molecular cloud or an exceptionally close stellar passage would introduce such an asymmetry; this would also be true for the unseen hypothetical stellar companion of the Sun recently invoked to explain the periodicity of the geological extinction of species through violent cometary showers.
Some remarks about the aphelion distribution of long period comets on the sky
Authors: Lüst Rhea
Published: July 2016

The possibility of an observational biasing in the distribution of cometary aphelia is confirmed by statistics. Furthermore, the tendency of aphelia to form clusters and their distribution with respect to different coordinate systems is investigated.
Interrelations between comets and asteroids
Authors: Rickman Hans
Published: July 2016

Various aspects of comet/asteroid distinctions and interrelations are reviewed with emphasis on recent work and paying special attention to the following problems: characteristics of cometary activity at large heliocentric distance and uniqueness of comet P/Schwassmann-Wachmann 1 with respect to physical properties, the rôle of Trojans and other small bodies in the outer planetary system concerning comet/asteroid classification, possibilities for physical evolution of comets into asteroids, orbital and dynamical overlap of the comet and asteroid populations, and the cometary versus asteroidal origin of Earth-approaching asteroids. With regard to these latter questions it is argued that recent discoveries indicate a more substantial probability for Jupiter family comets to develop into asteroidal objects than earlier believed, and several examples of cometary association for newly discovered Apollo-Amor asteroids are also referred to. However, the fractional cometary contribution to the traditional Apollo-Amor asteroid population (aphelia far inside Jupiter’s orbit) apparently can not yet be reliably estimated.
On the rotation of cometary nuclei and small asteroids
Authors: Farinella P. , Paolicchi P. , Zappala V.
Published: July 2016

The spin rate distributions of comet nuclei and small asteroids are compared, and it is shown that Whipple’s (1982) finding of a faster average rotation for the asteroid sample was due to observational biases. In fact, the presently available rotational data do not exhibit any clear differentiation among comet nuclei and asteroids, except possibly for a higher abundance of short rotational periods among the Apollo-Amor objects.
The orbital evolution of meteor streams at the 2/1 resonance with Jupiter
Authors: Froeschlé Cl.
Published: July 2016

We investigated the orbital evolution of Quadrantid-like meteor streams situated in the vicinity of the 2/1 resonance with Jupiter. For the starting orbital elements we took the values of the orbital elements of the Quadrantid meteor stream except for the semi-major axis which was varied between a = 3.22 and a = 3.34 AU. We considered these meteor streams as a ring and we investigated the resonant effect on the dispersion of this ring over a period of 13 000 years. Only gravitational forces due to the Sun and due to Jupiter were taken into account.
Statistical and numerical studies of the orbital evolution of short-period comets
Authors: Carusi A. , Valsecchi G.B.
Published: July 2016

The evolutionary paths connecting cometary reservoirs in the outer solar system and the population of periodic comets involve stellar and planetary perturbations. Close planetary encounters play a special role, making the dynamical evolution slow or fast depending on the orbital elements of the comet at various stages of the process. In this paper numerical work done in the last decades on this subject, using both real and fictitious objects, is reviewed.
The aging and lifetimes of comets
Authors: Kresák Lubor
Published: July 2016

The aging of comets is evidenced by a number of observable phenomena: production of gas, dust and meteor particles, splitting of cometary nuclei, nongravitational effects in the comet’s motion, sudden and progressive absolute brightness variations, and ultimate disappearance. Statistical data on comet losses, absolute magnitudes and orbits also bear signatures of their aging. The knowledge of potential active lifetimes of individual objects is a prerequisite of any realistic model of the long-term evolution of the whole comet complex. This paper reviews different sources of information on the aging process and summarizes implications for the mean lifetimes of comets, their dispersion and dependence on the orbital parameters. Two alternative end fates of comets - their total disintegration or change into an inactive asteroid-like object - are also discussed.
Planetary perturbations, dynamical energy and evolution of orbital elements of periodic comets
Authors: Manara A. , Buffoni L. , Scardia M.
Published: July 2016

Planetary perturbations, dynamical energy and orbital evolution of the elements of three comets are calculated. This paper presents a part of the catalogue that will be issued in the next year.
The International Cometary Explorer (ICE) Mission to comet Giacobini-Zinner (G/Z)
Authors: Brandt J.C. , Farquhar R.W. , Maran S.P. , Niedner M.B. , von Rosenvinge T.
Published: July 2016

The ICE spacecraft will pass through the tail of P/Giacobini-Zinner on September 11, 1985, to make in situ measurements of particles, fields, and waves that will contribute significantly to the knowledge of plasma tails and other aspects of the cometary/solar wind interaction. By obtaining data on the downstream side of G/Z, the ICE will complement the later upstream measurements obtained by the Comet Halley probes.
An Isophote Map of the Zodiacal Light in V
Authors: Pfleiderer J. , Leuprecht G.
Published: July 2016

The reduction method and the results of a photoelectric surface photometry of the Zodiacal Light at a wavelength of 555 nm are presented. A comparison with published results is also given.
Recent Rocket Observations of the Ultraviolet Spectrum of the Zodiacal Light
Authors: Feldman P.D. , Cebula R.P. , Tennyson P.D. , Henry R.C.
Published: July 2016

Observations of the spectrum of the zodiacal light in the wavelength range 1800-3000 Å have been obtained in two recent sounding rocket experiments. The September 1979 observation was made close to the ecliptic plane at elongation angles of 20° and 28° and with a spectral resolution of 25 Å, while in April 1981 the elongation was 125° (inclination 60°), and the spectral resolution 50 Å. Both observations confirm the slight reddening in the ultraviolet reported previously and show the same dependence on elongation as in the visible. There appears to be some structure in the ultraviolet albedo of the dust grains near 2800 Å but the exact nature of this structure cannot be determined at the low spectral resolution of the present observations. Detailed descriptions of the two observations has been given by Cebula and Feldman (1982) and Tennyson (1983), respectively.
A Search for Small Scale Structures in the Zodiacal Light
Authors: Hong S.S. , Misconi N.Y. , van Dijk M.H.H. , Weinberg J.L. , Toller G.N.
Published: July 2016

Gegenschein observations from Pioneer 10 were found to have brightness structures with an amplitude of about 10% and a period of several to ten degrees in elongation. A search is made for such structures in high angular resolution ground-based observations from Mt. Haleakala, Hawaii. A new empirical method is used to correct for atmosphere-originated radiation. Background starlight is subtracted using Pioneer 10 observations from beyond the asteroid belt. Preliminary analysis of the ground data also indicates the presence of small amplitude structures in the brightness distribution.
IRAS Observations of the Interplanetary Dust Emission
Authors: Hauser M.G. , Gautier T.N. , Good J. , Low F.J.
Published: July 2016

The Infrared Astronomical Satellite (IRAS) has completed a sensitive, highly redundant survey of the full sky in four broad photometric bands at 12, 25, 60, and 100 micrometers wavelength. The survey measured interplanetary dust emission over elongation angles ranging from 60 to 120 degrees. Bright emission from the main cloud is consistent with optically thin blackbody emission. The grains are evidently quite black, with an “apparent albedo” of about 0.07. The data show clear evidence for deviation of the dust symmetry surface from the ecliptic plane. Surprising bands of emission were discovered near the ecliptic plane and about ten degrees on either side of it. The heliocentric distance of this material, suggested to be asteroidal in origin, is inferred to be about 2.5 AU from both color temperature and parallax measurements.
A Balloon Observation of the Thermal Radiation from the Circumsolar Dust Cloud in the 1983 Total Eclipse
Authors: Maihara T. , Mizutani K. , Hiromoto N. , Takami H. , Hasegawa H.
Published: July 2016

During the totality on June 11, 1983 in East Java, Indonesia, a near infrared photometric observation of the solar corona was made using a stratospheric balloon, which was successfully launched by a joint team of ISAS, Japan and LAPAN, Indonesia. The surface brightness distributions in four near infrared bands: at 1.25, 1.65, 2.25 and 2.8 μm, have been obtained in the outer coronal region. Noticeable excess emissions superposed on the strong coronal background emission have been recorded in the scan profiles at 1.25 and 1.65 μm, and less conspicuously at 2.25 μm as well, at about 4 R⊙ from the sun. From the observed spectral and spatial characteristics, the excess emission component appears to originate in the thermal radiation from the circumsolar dust ring made of relatively large particles of about 100 μm in radius and with the olivine-like optical properties.
On the Earth’s Dust Envelope
Authors: Barsukov V.L. , Nazarova T.N.
Published: July 2016

The data of studying meteoric particles on Elektron-1 and Elektron-3 space vechicles were processed in a new way which made it possible to get the first idea of the Earth’s dust envelope structure. Meteoric matter is distributed in it not unformly, but as aggregations of particles moving around the Earth in more or less stable orbits at certain distances from the Earth’s surface.
Measurements of the Elemental and Isotopic Composition of Interplanetary Dust Collected on LDEF
Authors: Fechtig H. , Hörz F. , Igenbergs E. , Jessberger E. , Kuczera H. , Lange G. , Pailer N. , Sutton S. , Swan P. , Walker R. , Zinner E.
Published: July 2016

A passive interplanetary dust collection experiment, currently in orbit aboard LDEF (Long Duration Exposure Facility), is described. The collectors, germanium target plates covered by metallized Mylar foils, are designed for secondary ion mass spectrometry (SIMS) measurements of the elemental and isotopic compositions of residues resulting from micrometeoroid (> 10−10 grams) impacts. Impact simulation experiments have demonstrated the validity of the collection concept. Quantitative elemental analyses are complicated by the non-uniform distribution of projectile-derived elements.
A Discover of Iron Spherules with Golden Ni-Fe Core and Silicate Spherules With Golden Ni-Fe Inclusion in Deep-Sea Sediments
Authors: Hanchang Peng , Shijie Zhuang , Zhenkun Liu , Zhong Yu
Published: July 2016

Recently, we found iron spherules with golden Ni-Fe core and silicate spherules with golden Ni-Fe inclusion in deep-sea sediments. This finding is of significance for further understanding of the origin of the deep-sea spherules.
26A1/10Be in Deep Sea Spherules as Evidence of Cometary Origin
Authors: Raisbeck G.M. , Yiou F. , Klein J. , Middleton R. , Brownlee D.
Published: July 2016

Using accelerator mass spectrometry the cosmogenic isotopes 26A1 (half-life 716,000 years) and 10Be (1.5 × 106 years) have been measured in deep sea magnetic spherules. Because 26A1 can be abundantly produced by relatively low energy solar flare particles, while 10Be is mainly produced by higher energy galactic cosmic rays, the ratio 26Al/10Be of a body irradiated in space increases as the size of the body decreases. Our measured ratios of 26Al/10Be in the spherules are much larger than found in meteorites, and indicate irradiation in interplanetary space of a parent body of ≲ 1 cm diameter. Since most bodies of this size entering the atmosphere are associated with cometary orbits, our results strongly suggest that these spherules represent cometary debris. Our results also suggest an irradiation time in space of the order of 106 years for the parent bodies.
Chemical and Isotopic Compositions of Refractory Elements in Deep Sea Spherules
Authors: Yamakoshi Kazuo , Honma Koichi
Published: July 2016

In order to study the inhomogeneity of the solar materials at the initial state, the enrichment factors and isotopic anomalies of refractory elements in deep sea spherules relative to the average solar abundance were examined using instrumental neutron activation analysis. Fairly high enrichment factors and isotopic anomalies of refractory elements were observed in several spherules, however, after the ablation process of the spherules during the atmospheric heatings they were not inconsistent with those of normal values in the solar system.
Remote Sensing of the Zodiacal Cloud along Secants to Earth’s Orbit
Authors: Dumont René , Levasseur-Regourd Anny-Chantal
Published: July 2016

Partial but significant localization along the line of sight (l.o.s.) of the contributions to the integrated zodiacal brightness can be achieved, without recourse to rash physical assumptions, if we focus on the two intersections between the l.o.s. and the terrestrial orbit. Then, there exists on the l.o.s. two other points or “nodes”, the contributions of which can be retrieved with outstandingly low uncertainty. The photometric results at these nodes (heliocentric change of scattering efficiency, backscattering phase function etc.) are highly reminiscent of previously ascertained features, and they encourage extensions to the polarimetric, the spectrometric and the radiometric cases. The salient results are, respectively: a positive radial gradient of local polarization degree; orbital velocities in excess over the keplerian ones, at least outside the earth’s orbit; the derivation of local temperatures from IRAS data.
Experimental Results on Scattering by Irregular and Meteoritic Dust Particles Related to Photopolarimetry of Zodiacal Light and Comets
Authors: Weiss-Wrana K. , Giese R.H. , Zerull R.H.
Published: July 2016

The investigations of light scattering by larger meteoritic and terrestrial single grains (size range 20 μm to 120 μm ) demonstrate that the scattering properties of irregularly shaped dark opaque particles with very rough surfaces resemble the characteristic features of the empirical scattering function as derived from measurements of the zodiacal light. Purely transparent or translucent irregularly shaped particles show a quite different scattering behaviour. Furthermore irregular and multicomponent fluffy particles in the size range of a few microns were modelled by microwave analog measurements in order to explain positive and negative polarization of the light scattered by cometary dust grains.
On the Bimodal Nature of the Particle-Size-Distribution Function of Cometary Dust
Authors: Liu C.P. , Kimura H.
Published: July 2016

The bimodal nature of distribution function f(γ) is confirmed by analysing the optical isophotal maps of comets Kohoutek 1973 XII and Bennett 1970 II. Extending the dynamic analysis to the infra-red data of two comets, Kohoutek 1973 XII and IRAS-Araki-Alcock 1983 d, we demonstrate that the secondary component f2(γ), which dominates in the range of large particles, plays a much more important role in emitting the thermal radiation (IR) than in the case of light scattering (optical). The relative weight of two components, measured by their height ratio, g2/g1, should be increased by a factor of about 20, in order to obtain a good fitting to the infra-red data.
On the Electrical Effects of the Presence of Fluff on the Surface of Cosmic Dust Grains
Authors: Lafon J.P. , Millet J.M.
Published: July 2016

We give a n analytical model describing the effects of “fluff” on the potential and the electric field on and close to a charged spherical body embedded in an astrophysical plasma. The consequences are investigated for dust grains biased at positive or negative potentials but large enough for electron or ion field emission to be active.
Dynamics of Dust Particles in the Solar System
Authors: Burkhardt G.
Published: July 2016

This short communication is part of a thesis at the University of Heidelberg, FRG.

It deals with some dynamical aspects of small interplanetary particles, which are affected by non-gravitational forces like the Poynting - Robertson Effect.

The equations of motion of test particles are numerically integrated. The forces acting on these particles include the gravitational attraction of the Sun and the Planets as well as forces due to incident solar radiation.

The ephemerides of the Planets in the heliocentric rectangular 3-dimensional coordinate system used here are taken from the Development Ephemeris DE-102 (Newhall et al. 1983) . This restricts the time span of the integration to about 4412 years.
Observational Evidence for Coronal Magnetic Reconnection During the Two-Ribbon Flare of 21 May 1980
Authors: Kopp R.A. , Poletto G.
Published: July 2016

The 21 May event was a large two-ribbon flare which occurred in active region 2456 at S13W15. The flare was extensively documented by coordinated Hα, X-ray, and magnetograph observations. In particular, spatially resolved images in hard X-rays were obtained by the Hard X-ray Imaging Spectrometer (HXIS) aboard SMM. Hence this flare comprises an ideal example for studying the spatial relationship between the X-ray and Hα-ribbon morphologies. Although evidence has been reported for magnetic flux emergence at the beginning of this flare (Harvey, 1983), it appears that a potential field (rising source-surface) model may adequately represent the major large-scale features of the magnetic configuration believed to result from fieldline reconnection in the corona during the decay phase (Kopp and Pneuman, 1976).
Broad-Band Spectroscopy of Late-Type Stars with Exosat
Authors: Landini M. , Monsignori-Fossi B.C. , Pallavicini R.
Published: July 2016

We analyze 6–300Å observations of late-type stars obtained with EXOSAT. We discuss the problem of deriving source temperature and other physical parameters from broad-band EXOSAT observations.
The Solar X-Ray Line Spectrum 5.5 – 12Å
Authors: McKenzie D.L.
Published: July 2016

The SOLEX X-ray spectrometers on the USAF P78–1 satellite have measured solar X-ray spectra in the 5.5–12Å range under a variety of flaring and nonflaring conditions. High sensitivity, obtained by summing data from several successive spectral scans, enabled the detection of 80 lines, 17 of which remain unidentified. The stronger lines were observed with individual scans during the course of flare development. This capability, along with the use of nonflare spectra, facilitated the identification of several lines. The lines of Fe XXII - XXIV, present in hot flare plasmas, are prominent in this wavelength range. For many of these lines, theoretical and observed line strengths will be compared. Diagnostically useful line ratios were evaluated for the helium-like species Mg XI, Al XII, and Si XIII. The density-sensitive R ratio was consistent with theoretical calculations of the low-density limiting value for Mg XI and Si XIII, the only species for which it was evaluated. In all cases the G ratio was below calculated values.
Photodissociation of Neutral Free Radicals of Astrophysical Interest
Authors: Gardner L.D , Graff M.M. , Kohl J.L.
Published: July 2016

The necessity for understanding molecular formation and destruction processes occurring in astrophysical environments is well known. Accurate molecular data are of critical importance in formulating models of such diverse regions as interstellar clouds and planetary and stellar atmospheres. With this in mind we have devised an experimental method and constructed an apparatus for the determination of cross sections as well as the kinetics for photodissociation processes in chemically unstable neutral molecules. Similar experimental methods have been independently developed by de Bruijn and co-workers and by Chen et al.
Critical Compilations of Atomic Energy Levels
Authors: Sugar J. , Martin W.C. , Reader J. , Musgrove A. , Corliss C.
Published: July 2016

We have been publishing new compilations of energy levels for single elements in all stages of ionization as each is completed. Those now in print in the Journal of Physical and Chemical Reference Data are helium (1973), sodium (1981), magnesium (1980), aluminum (1979), silicon (1983), potassium (1979), calcium (1979), scandium (1980), titanium (1979), vanadium (1978), chromium (1977), manganese (1977), iron (1982), cobalt (1981) and nickel (1981). A volume containing atomic energy levels of all rare earth elements was issued in 1978. We have now updated our compilations for the iron period (K through Ni, 235 spectra), which will be published in a single volume.
Interpretation of Pseudocontinua in the Spectra of Highly Ionized Atoms from Tm To W in Laser Produced Plasmas
Authors: Mandelbaum P. , Klapisch M. , Krasnitz A. , Zigler A.
Published: July 2016

X-ray spectra of highly ionized atoms (Tm to Pt) emitted from Laser produced plasma are characterized by the simple structure given by resonant transitions of the Nil-like ions, accompanied by the more complex pattern of satellite transitions emitted by ions in the neighbouring states of ionization. An analysis of these structures has been given recently for the satellites of the 3d10 − 3d94p[l] and of the 3p63dl0 − 3p53d104s, 4d[2] transitions of the Nil-like inns. However, most of the radiation emitted in this spectral range [4–10Å] concentrate in a wide, rather structureless satellite feature in the long wavelength side of the 3d10 −3d94f Ni-I like transition, on which some lines are superimposed. Line identification has been achieved successfully with the methods of [1], [2] and will be published separately. In this communication, we deal only with the pseudocontinuum.
Electron Capture into Excited States for Al8+ + H2 Collisions at 3 keV/amu
Authors: Mayo M. , Hitz D. , Druetta M. , Dousson S. , Desclaux J.P. , Bliman S.
Published: July 2016

The MINIMAFIOS ECR source at Grenoble has recently produced stable beams of highly charged Al. We have studied electron capture into excited states for Al8+ ions extracted at 10 kV colliding with an H2 molecular target under single collision conditions. Using a grazing incidence spectrometer covering the region 250 Å to 1100 Å, we have made a relative intensity measurement of the radiative decay from excited (nl) states of Al7+ following the charge exchange collision. The Al7+ spectra show known transitions from the ls22s2p3 excited state. We discuss the presence of the ls22s2p2(4P) metastable state in the incidence Al8+ beam. The spectra also show many transitions which up to now are unidentified, in particular transitions for the wavelength region between 300 and 400Å and that between 600 and 700Å. To identify the transitions, we compare our spectrum with preliminary theoretical wavelengths calculated using the multiconfiguration Dirac-Fock method including transitions from n = 3, 4 and 5. These preliminary results reveal transitions from n = 5 to 4 for the observed spectra in the 600Å region and transitions from n = 4 to 3 for the observed spectra in the 300Å region.
Direct Comparison of Electron Density Measurements in Laser-Created Plasmas Using Stark Broadening and Satellite Line Intensities
Authors: Alaterre Ph. , Audebert P. , Geindre J.P. , Monier P. , Popovics C. , Gauthier J.C.
Published: July 2016

Spectral line profiles, broadened mostly by Stark effects from electric fields produced by charge particles, and diélectronic satellite line intensities have recently been used for determining electron densities in the dense region of laser-created plasmas. We present here a direct comparison of electron density measurements in the conduction region of laser created plasmas on a plane target using these two techniques.

Experiments were carried at the GRECO laser facility, using the Nd phosphate glass laser at its second harmonic (0.53 μm) and 600 ps pulse length. The laser was focused on a 160 μm focal spot in which was centered a 25 or 50 μm diameter aluminum dot implanted on a carbon substrate. Laser intensities were in the range 1 × 1014−3 × 1014 W/cm2. The ls4p−ls2 He-like transition, the 4p−ls H-like transition and the Ly c satellites were recorded on the same spectrum with a PET flat crystal spectrograph. Spot spectroscopy provided quasi-homogeneity and low reabsorption along the line of sight which was tilted 7° out the target surface. 3 μm resolution along the laser axis was obtained with an imaging knife-edge placed 1 mm apart from the target.
Absorption Spectra of Light Ions in the Extreme Ultraviolet
Authors: Jannitti E. , Nicolosi P. , Pinzhong F. , Tondello G.
Published: July 2016

We have used the method of two laser produced plasmas (Jannitti et al. 1984a) to measure the absorption spectra of the ions Be++ (Jannitti et al. 1984b), Be+ (Jannitti et al. 1984c) and B+ in the grazing incidence and normal incidence region. Both discrete and continua transitions have been measured and values of the photoionization cross sections are derived.

The experimental set up referring to the normal incidence investigation is shown in Fig. 1. A laser beam of 10 J of energy and 15 ns (FWHM) duration is split in two parts and generates two plasmas: one on target T of high atomic number (Cu) used as a background continuum emitting source and a second on target A for producing the absorbing species to be studied. For the latter a sphero-cylindrical lens is used producing a focal spot 100 µm wide and up to 10 mm long. The continuum radiation produced on a target tilted 45° both with respect to the laser beam and to the axis of observation was collected by a toroidal mirror whose radii of curvature, R = 640 mm in the plane of incidence and ρ = 530 mm in the plane perpendicular to the former are such to compensate the astigmatism of the 2 m radius grating.