bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiative Damping of Gravity Waves in the Solar Atmosphere
Authors: Logan Jerry D. , Hill Henry A. 
Published: July 2016

AbstractThe nonlocal character of the radiation field sinnificantly modifies the radiative damping of perturbations in the solar photosphere. Gravity waves are not usually considered to exist in the solar photosphere because the radiative damping time, when based on the Newtonian approximation, is too short. However, this restriction does not apply to low order gravity waves. In fact, with the inclusion of nonlocal effects, the radiative damping for low order gravity waves becomes negative for some region in the photosphere and thus acts as a driving mechanism for gravity waves there.
Delta Scuti Stars and Dwarf Cepheids: Review and Pulsation Modes
Authors: Breger Michel 
Published: July 2016

AbstractRecent developments in the field of Delta Scuti stars are discussed. Considerable progress has been made in determining the multiple-period structure of individual variable stars and in identifying the excited radial and nonradial modes through a variety of methods. This allows an analysis of the change of excited modes as a function of the position in the instability strip.
The Effect of Stellar Structure on Supernova Remnant Evolution
Authors: Jones Eric M. , Smith Barham W. , Straka William C. 
Published: July 2016

1. AbstractOne-dimensional hydrodynamic calculations have been done of 1E51 erg explosions in 15M⊙ stars. We have appended a steep external density gradient to the pre-supernova model of Weaver et al and find: (1)	the outer shock wave decelerates throughout the pre-Sedov phase, (2) the expanding stellar envelope and the shocked interstellar material are Rayleigh-Taylor stable until the Sedov phase, and (3) steep internal density gradients are R-T unstable during the early expansion and may be the source of high velocity knots seen in Cas A.
Hydrodynamic Modeling of Mass Loss from Cataclysmic Variable Secondaries
Authors: Gilliland Ronald L. 
Published: July 2016

AbstractResults of detailed computer simulations of mass loss from a cataclysmic variable secondary are presented. The calculations involve solution of the nonlinear hydrodynamical equations of stellar structure under varying degrees of approximation in an attempt to determine stability of the mass loss process. For comparison with previous theoretical studies dynamical sequences were computed assuming spherically symmetric mass loss from the secondary. The assumption of spherical symmetry is very poor since nearly all of the transferred material is lost within a small region about the inner Lagrangian point. Dynamical sequences treating only the region near the Lagrangian point were constructed in a manner consistent with the assumption of Roche geometry. Finally the effects of mass flow nonorthogonal to the Roche equipotential surfaces were treated in a very simple way. The last generalization produces stable mass loss in a model which was unstable for the less realistic approximation schemes. The finding of stable mass transfer implies that instability of the secondary star is not the mechanism leading to cataclysmic variable outbursts. This conclusion is consistent with published observations of dwarf novae made just prior to outburst.
The Satellites of Uranus
Authors: Cruikshank Dale P. 
Published: July 2016

AbstractThe Uranian satellite system contains five known members, all of which are difficult to study owing to their faintness and proximity to Uranus. The photometry of these objects is not in a satisfactory state, nor is the photovisual spectrophotometry. Infrared observations are in some sense easier and more precise because Uranus itself is faint in the near infrared and interferes but little with the satellite studies. The near infrared work reveals water ice or frost on the satellite surfaces, perhaps in a very pure state. The satellites are most similar to Ganymede in terms of the strength of the ice bands, but subtle differences, now under study, may be present. The diameters and masses of the satellites, while not readily measurable directly, can be estimated from generalizations about the surface geometric albedos, assumed mean densities, and certain dynamical arguments. Most of the data and theories are consistent with bodies with radii in the range 160-520 km (similar to the larger asteroids) and albedos on the order of 0.5, consistent with ice and snow. The mean densities are probably similar to those of the icy Saturn satellites, about 1.3 g/cm3. Uranus’ satellites probably formed after the event that caused the planet to tilt to the presently observed obliquity.
Uranus Science with Space Telescope
Authors: Caldwell John 
Published: July 2016

AbstractThe Space Telescope Observatory, scheduled for launch in 1985, is described. The advantages of the space environment and the consequent features of ST performance are given, with Uranus observations as examples. The first generation instruments, including two cameras, two spectrographs and a high speed photometer, are discussed. The Space Telescope Science Institute, which will manage the Observatory, is discussed briefly. The potential scientific interaction with the Voyager 2 encounter of Uranus is also considered.
The Astronomical Data Base and Retrieval System at NASA
Authors: Mead Jaylee M. , Nagy Theresa A. , Hill Robert S. , Warren Wayne H. 
Published: July 2016

AbstractMore than 250 machine-readable catalogs of stars and extended celestial objects are now available at the NASA/Goddard Space Flight Center (GSFC) as the result of over a decade of catalog acquisition , verification and documentation. Retrieval programs are described which permit the user to obtain from a remote terminal bibliographical listings for stars; to find all celestial objects from a given list that are within a defined angular separation from each object in another list; to plot celestial objects on overlays for sky survey plate areas; and to search selected catalogs for objects by criteria of position , identification number, magnitude or spectral type.
Activities of the Potsdam Data Center
Authors: Schilbach E. 
Published: July 2016

In 1968 the Data Centre was established in the Central Institute for Astrophysics of the Academy of Sciences(CIAP) of the German Democratic Republic. Its task was essentially the analysis of astronomical observations and the elaboration of theoretical models for astronomical problems.In 1974,a cooperation was started between our institution and the Stellar Data Centre at Strasbourg.
New developments in data storage
Authors: Grosbøl P.J. 
Published: July 2016

AbstactIt is estimated that up to 100 Gbytes of primary data from digital detectors have to be stored each year. The amount of reduced data is at least one order of magnitude smaller. Although the storage density for magnetic recording can be made higher, only the optical technic can provide a substantial denser medium than the photographic emulsion. It seems likely that optical read-only devices will be developed for archival storage of data in this decade. Magnetic recording of data will still be preferred whenever changing of the information is important.
Digital Image Processing and Data Retrieval : The Needs
Authors: Bijaoui A. 
Published: July 2016

During the last decenny, Digital Image Processing (D.I.P.) has been introduced in astronomical studies to allow the information extraction.In a first step, D.I.P. has been used essentially to provide enhanced images (noise reduction, deconvolution, contrast enhancement), to reduce geometrical or photometrical distorsions and to extract rough data. So, a few reference date are needed (some comparison lines for example).
International standards for software structures in astronomy
Authors: Pucillo M. , Santin P. , Sedmak G. 
Published: July 2016

AbstractThe increasing request for astronomical data processing facilities forces the definition of standards for astronomical application software. Separating the application module from the interfaces to the data processing system allows to identify the standard user interaction interface, the standard data storage interface, the standard dedicated subsystems interface and the standard on-line documentation interface. We tested a tentative integrated solution that fulfills these requirements. This solution includes colour graphics and is available to the astronomical community.
INSPEC activities in astronomy and astrophysics
Authors: Collins Mike J. 
Published: July 2016

Considers a typical paper from the astronomical literature, shows how it was processed for ‘Physics Abstracts’ and illustrates how it can now be retrieved on-line from the INSPEC database.“Two-color photoelectric observations of the eclipsing binary BB Peg” by Cerruti-Sola and Scaltriti was published in Astronomy & Astrophysics Supplement Series, Vol. 40, No. 1, p. 85–9 (April 1980). The abstract for this paper appeared as No. 62194 in Physics Abstracts, Vol. 83, No. 1139, p. 4806 (1 July 1980). This particular journal article has been chosen to illustrate the way material is handled by the INSPEC database because apart from the usual bibliographic elements, a designated stellar object (BB Pegasi) is mentioned and numerical data (observation dates) are incorporated.
Editorial policies
Authors: Lequeux James 
Published: July 2016

AbstractA short summary of the way the main astronomy journals are produced is given. The different ways of publishing a scientific journal are described, their advantages anddrawbacks-are discussed and some projections towards the future are made. We finally deal with a few specific editorial topics : publication of large collections of data, designation of astronomical objects, indexing and retrieval of information.This paper reflects my opinions concerning what a journal like Astronomy and Astrophysics is presently doing, could reasonably do and will possibly do in the future in order to publish the material submitted by the astronomical community. I have had contacts with Prof. B.J. Tayler, the Managing Editor of the Monthly Notices of the Royal Astronomical Society, and some of his opinions are conveyed here.
A list of standard star designation
Authors: Ochsenbein F. , Spite F. 
Published: July 2016

AbstractSome rules about star designation have been edicted by Commission 5 of the IAU : they are briefly recalled and discussed. The essential rule, to be kept in mind by every author, is : when quoting a designation of a star, always quote the complete bibliographic reference of the paper defining this star designation. “Standard” designations can be an exception to this rule : it is proposed to publish in the CDS Bulletin a list of designations considered as “standard”; the authors would be relieved of the obligation of quoting the references of these “standard” catalogues and could concentrate on the task of referencing the other catalogues.
On the nomenclature of diffuse fragmentary objects
Authors: Polechova P. 
Published: July 2016

AbstractFor the purpose of Cataloguing diffuse objects in a wide range of dimensions, two alternative proposals are presented.Problems similar to those discussed in connection with the nomenclature of optical HII-regions may occur with any diffuse objects such as molecular clouds, large reflection nebulae, HI-regions, and, of course, radio HII-regions.The radio HII-regions are most commonly designated by the galactic numbers “G”. The galactic longitude forms the first part of this number, the galactic latitude the second part, both parts being usually accurate to the first decimal digit and separated by the sign of latitude. This system (also used sometimes for optical objects) was introduced by Mezger and Henderson (1967) in a survey at 5 GHz, with a half power beam width of the telescope of about 6'. The angular dimensions of their objects were in the range from 3 to 11'.
Data and Data Retrieval in Space Astronomy
Authors: Vette J.I. 
Published: July 2016

AbstractTo illustrate the range of storage and retrieval facilities and data products that are involved in space astronomy, the present situation on data from some instruments on the following missions is presented: Small Astronomy Satellite-B, Orbiting Astronomical Observatory 3, High Energy Astrophysics Observatory 2, International Ultraviolet Explorer, Viking Orbiter, and Solar Maximum Mission. In addition the Coordinated Data Analysis Workshops conducted at the National Space Science Data Center are outlined to demonstrate the usefulness of building a problem-oriented on-line data base from instruments flown on a number of spacecraft and operating from ground-based facilities.
Optical System for the University of Texas 7.6m Telescope
Authors: Tull R.G. , Barnes T.G. , Dittmar D.N. , Ray F.B. , Pearson Earl 
Published: July 2016

As presently conceived, the large telescope now being planned at The University of Texas will have a Ritchey-Chrétien configuration, f/13.5, with a 7.6m diameter f/2 primary of ultra-thin construction, on an alt-azimuth mount.In this paper we will describe the current concept for the mounting, the building, mirror handling techniques, and the optical system. We will give preliminary results of the finite element flexure analysis of the mirror on its support system.Studies have demonstrated a workable concept and have shown that there exists a method of adequately supporting an ultra-thin mirror against gravity and wind loads. We are continuing these studies, including also thermal effects on the mirror figure, in order to determine the best choice of mirror material and construction at the most reasonable price.
Aerodynamic and Thermal Problems Around and Inside a Dome and Telescope
Authors: Rösch Jean 
Published: July 2016

AbstractMuch effort has been spent at Pic-du-Midi, with increasingly large telescopes, to reduce the instrumental causes of image deterioration and take best advantage of local atmospheric conditions. With the new 2-meter reflector, specifically intended for high resolution imaging, the concept has been, ideally, to separate three air-masses: outside, inside the tube, and inside the dome. As a first step, no parallel plate of required size and quality being available, the tube is open to the outer air, but a connection between tube and dome aims at preventing the dome-air flowing across the light-beam. Results and expectations are presented.
Multi-Order Formats to Increase the Versatility of Cassegrain Spectrographs
Authors: Harmer Dianne L. 
Published: July 2016

Abstract“Grism” and compound prism cross-dispersers have been proposed for the new Cassegrain spectrograph of the 2.5m telescope at La Palma. The RGO image-tube spectrograph has been fitted with a grism to provide us with experience in designing layouts, operating the equipment and handling the data.
High Angular Resolution with Rotation Shearing Interferometers: Preliminary Results and Future Potentials
Authors: Roddier F. , Roddier C. 
Published: July 2016

Compared to speckle-interferometry, amplitude-interferometry has the following advantages:
(1) The amplitude of the object Fourier components is insensitive to both turbulence and telescope induced aberrations, permitting an accurate calibration of visibility curves,(2) Interferograms are free from speckle noise, permitting a better signal-to-noise ratio on bright sources,(3) Information can be retrieved from fewer exposures (including complete image reconstruction),(4) Accurate visual measurements of stellar diameters and of the angular spacing of binary stars can be easily performed.
A High Resolution Fourier Transform Spectrometer for the Cassegrain Focus at the CFH Telescope
Authors: Maillard Jean P. , Michel G. 
Published: July 2016

AbstractA high resolution interferometer (60cm maximum path difference) for use from the visible region to 5μm has been designed and manufactured at Meudon Observatory to be part of the instrumentation of the Canada-France-Hawaii Telescope. The considerations which led to the choice of the interferometer being operated at the Cassegrain focus, and the design features which allow this to be achieved, are outlined.
Stellar perturbations on comets
Authors: Remy F. , Mignard F. 
Published: July 2016

AbstractThe stochastic processes involved in the evolution of a hypothetical cloud of comets are investigated. The cloud is assumed to be randomly perturbed by passing stars approaching the Sun at distance less than 1 pc. Within the frame of the impulse approximation we derive analytical expressions for the probability distribution of the impulse imparted to comets for both close and distant approaches. An application to the rate of ejection of comets is presented.
Errors in numerical integrations and chaotic motions
Authors: Milani A. , Nobili A.M. 
Published: July 2016

AbstractThe methods to estimate the integration errors, including the effects of truncation, rounding off, and instability of the solutions, are discussed. Polynomial error accumulation depends upon numerical method, stepsize, orbital period and also eccentricity; it is also machine dependent. Comets correspond to the most difficult case of exponentially diverging orbits; however they can be very close to resonant ordered regions.
The past orbit of comet Halley and its meteor stream
Authors: Hajduk A. 
Published: July 2016

AbstractThe present paper studies the structural features of the meteor streams associated with Comet Halley deduced from the observations of its meteor showers, as check points of orbital elements in a deeper history of the comet orbit. Libration of the argument of perihelion of the comet and the corresponding displacement of the nodes, as recognized in the distribution of condensations within the stream, allows to estimate the maximum lifetime of the comet in the inner Solar System at about 2 × 105 years.
Ground-Based Observations of Near Ecliptic Zodiacal Light Brightness
Authors: Misconi Nebil Y. , Weinberg J.L. 
Published: July 2016

AbstractGround-based observations of the evening zodiacal light taken by Weinberg and Mann from Mt. Haleakala, Hawaii, during March 1966 are used to derive a table of zodiacal light brightnesses at high spatial resolution (as little as 0.5° in differential ecliptic longitude λ−λ⊙ and 1.0° in ecliptic latitude β) over the region 29. 5°< λ−λ⊙ < 56°, −30°< β <30°. Significant differences are found in the brightness distributions above and below the ecliptic plane.
The Change in Near-Ecliptic Zodiacal Light Brightness with Heliocentric Distance
Authors: Toller G.N. , Weinberg J.L. 
Published: July 2016

AbstractBackground starlight observed by the Pioneer 10 Imaging Photopolarimeter from beyond the asteroid belt is used to isolate zodiacal light in Pioneer observations at heliocentric distances R between 1 and 3 AU. Near-ecliptic zodiacal light brightness data in the range 65° to 180° elongation ε are used to depict changes in the shape of the zodiacal light with ε and R and are compared to the corresponding views seen from the Earth and from the Helios 1 and 2 spacecraft.
On the Solar Dust Ring(s)
Authors: Mukai T. 
Published: July 2016

AbstractBased on a mechanism to form the solar dust ring, it is proved that the observed peak in infrared F-corona cannot be explained by silicate type grain alone. Preliminary analysis on the recent infrared data of F-corona by Maihara et al.(1984) has suggested that the ring particle has different physical properties compared with the dust grains, which produce the background F-corona.
Interpretation of F-Corona Radial Velocity Field
Authors: Shestakova L.I. 
Published: July 2016

AbstractThe radial velocities of F-corona for total eclipse July 31, 1981 obtained at elongations (3-7) R⊙ are interpretated assuming prograde motion in circular Keplerian orbits of circumsolar dust. In computations isotropic plus diffraction scattering functions are used. In supposition of silicate grains the best coincidence with observations is received for grains with radii about 0.4 μm with the presence of dust free zone (d.f.z.) around the Sun to heliocentric distances (6.5-14) R⊙ and high grain concentration at the edge of this dust free region.The presence of negative radial component of radial velocities can be explained by falling of the matter into the Sun under influence of Poynting-Robertson effect of solar wind for porous grains with radii less than 0.4 μm . The effect of radiation drag for these small grains is essentially less. Using grains with radii less than 0.4 μm the sizes of which decrease as approaching to the Sun one may explain the inner F-corona brightness.
Interferometric Observation of the F-Corona Radial Velocities Field Between 3 and 7 R⊚
Authors: Shcheglov P.V. , Shestakova L.I. , Ajmanov A.K. 
Published: July 2016

AbstractDuring the July 31, 1981 solar eclipse, F-corona interferograms near MgI λ 5184 Å were obtained using a Fabry-Perot etalon (FPE) with an FWHM of 0.5 Å (corresponding to 30 km/sec) and an image tube. Radial velocities Vr of the interplanetary dust (i.d.) were measured in different directions.Both prograde and retrograde motions of i.d. in the ecliptic region is discovered. Most of velocity values do not exceed 50 km/sec. A negative velocity component appears after averaging all Vr for all directions. Its average increases to − 20 km/sec toward the Sun. Some ejections are observed. The strongest (+ 130 km/sec) is located at the north ecliptic pole at a distance of 6 to 7 R⊙.From the lack of unshifted Fraunhofer lines in the scattered sky light, we conclude that the sky brightness continuous component is predominant and its source is K-corona scattered light in the Earth’ s atmosphere.
The Motion of Interplanetary Dust Particles
Authors: East I.R. , Reay N.K. 
Published: July 2016

AbstractRadial velocity measurements on the solar MgI 5183.618Å Fraunhofer absorption line in the Zodiacal Light spectrum have been made with a microprocessor-controlled servo-stabilised Fabry-Perot interferometer. Observations were made at 5 and 10 degree intervals in the ecliptic plane between morning and evening elongations of 25 degrees. These new data are of much greater precision and coverage than any previously obtained. Obtained over a two year period, the observations show a consistent evening/morning asymmetry in the radial velocity curve with the Gegenschein receding from the Earth at 4 Km/sec. These data do not support the hypothesis that the majority of interplanetary dust grains are in hyperbolic trajectories.
Orbits of Interplanetary Dust Particles Inside 1 AU as Observed by Helios
Authors: Grün E. , Fechtig H. , Kissel J. 
Published: July 2016

AbstractThe in situ dust detectors on board the Helios spaceprobes detected impacts of micrometeoroids between 0.3 AU and 1 AU distance from the sun. Among the measured quantities were mass, impact speed and flight direction of the dust particles. Radial variations of the flux, azimuthal distribution and impact speed are discussed. Significantly different results were obtained for the “apex” particles observed by both ecliptic and south sensors and for the “eccentric” particles detected only by the south sensor. The radial spatial density variation of the “eccentric” particles is compatible with that derived for zodiacal light particles. Whereas the spatial density of “apex” particles peaks at 0.5 to 0.6 AU. From the measured quantities probability distributions of orbital elements were derived for the observed micrometeoroids. About 60% of the observed micrometeoroids (“apex” particles) are on low energy orbits (a ≲ 0.6 AU). About 30% of the particles (“eccentric” particles) had high energy orbits (a ≳ 0.9 AU). More than 10% of the observed particles show high probabilities for travelling on hyperbolic orbits.