bluuebunny/crossref_metadata_2025 huggingface dataset:
Speckle Interferometry of Double Stars from the Southern Hemisphere
Authors: Horch E. , Van Altena W. F. , Girard T. M. , López C. E. , Franz O.
Published: June 2019

We have started a new program of double star observations in the southern hemisphere which utilizes the technique of speckle interferometry. Observations are made using the Stanford University speckle interferometer on the 76-cm reflector at the Cesco Observatory at El Leoncito, Argentina (jointly run by Universidad Nacional de San Juan and Yale Southern Observatory), although we will also have access to larger aperture telescopes. The Stanford system, formerly used at Lick Observatory, is on long term loan to us from Dr. Gethyn Timothy and features a multi-anode microchannel array (MAMA) detector as the imaging device. This new program of double star research will help alleviate the continuing problem of fewer speckle observations in the southern hemisphere. In combination with other data such as the eyepiece interferometer measures of Finsen and Hipparcos parallaxes, it should also eventually contribute to a better understanding of the lower portion of the main sequence mass-luminosity relation.
The Catalogue of the Components of Double and Multiple Stars (CCDM) - First Edition
Authors: Dommanget J. , Nys O.
Published: June 2019

The Hipparcos mission required the realisation of an Input Catalogue giving the positions of 100.000 stars (single or components of double and multiple systems) to an accuracy better than 1″5. At the start of this work (1981) no specific catalogue of double and multiple stars provided these data. The only general data base on double stars available to us, giving positions to ±1′, was the Index (1961,0) updated at the USNO by C. E. Worley till 1976,5 and of which a copy was communicated by P. Muller of the Observatoire de Meudon. It has then been decided to reformat this Catalogue in such a way as to allow the introduction of all necessary information for the mission. This permitted a correct cross-identification with the Hipparcos Input Catalogue (of finally 118.000 stars). It was later called: the Catalogue of the Components of Double and Multiple stars (CCDM). Since then, it has been developed and its aim remains to furnish the best accurate locations and descriptions of the double and multiple systems on the sky for all double and multiple star research.
A Dynamical Investigation of Nine Wide Visual Double Stars in the Neighbourhood of the Sun
Authors: Kisselev A.A. , Romanenko L.G.
Published: June 2019

The dynamical states of nine wide visual double stars (ADS 7251, 10329, 10386, 10759 [psi Dra], 11061 [40&41 Dra], 11632, 12169, 12815 [16 Cyg]) are considered. The 20-30 – year series of photographic observations obtained with the Pulkovo 26-inch refractor (Kisselev et al., 1988) supported by the data of relative radial velocities of the components and parallaxes are used. On this base the vectors of relative spatial positions and velocities of the components are determined or estimated with confidence. Families of orbits, satisfying observational data are determined by assuming stability of motions in the systems. The orbits of three nearby binaries ADS 7251, 11632 and 61 Cyg were calculated earlier by classical methods and belong to the family mentioned above. Thus the authenticity of our analysis is proved (Kisselev, Kiyaeva, 1980). It is shown that elliptical motion in the couples ADS 10759 and 11061 could be explained only if an additional (hidden) mass exists. This mass consists of one solar mass for the first couple and two solar masses for the second one. The dynamical orbital elements of the binaries belonging to each family may differ greatly, but the geometrical elements are fairly stable. The orientation of the orbit planes of binaries with respect to the Galaxy plane is determined. In one half of the cases the orbital planes are approximately orthogonal to that of our Galaxy.
Stand-Alone Program Package for Improvement of Parameters of Celestial Bodies Motion
Authors: Ivanova T. V. , Novikov F. A. , Pariiskaya E. Yu.
Published: June 2019

A stand-alone Program Package for Improvement (PPI) of motion parameters of celestial bodies from observations is described. The PPI is oriented for solving conditional equations system by the method of least squares and is implemented for IBM PC in MS-DOS in the Turbo-Pascal programming language v.5.0. There are two versions of the system:

A)

using the standard conventional memory 640 Kb and

B)

using the external memory.
Dark Matter in Triple Galaxies
Authors: Kiseleva Ludmila
Published: June 2019

On the basis of numerical simulation of the dynamics of triplets of galaxies, virial estimation of the individual masses of triplets is shown to be unreliable because of their strong nonsteadiness and projection effects: the spread in estimates due to these two factors reaches 2 orders of magnitude. However, the mass of a typical small galaxy group can be estimated statistically, from data on a whole homogeneous ensemble of groups. We propose two different methods of such statistical estimation. Triplets of galaxies offer a good opportunity to measure the amount of dark matter in them, especially because one can use the extensive data set on triplets by Karachentsev et al. (1989). The mass estimates we obtain for the typical group from the Karachentsev's list have more than 5 times excess compared to the visible mass, when a standard mass-to-light ratio is assumed. The typical masses of loose triple galaxies selected from Huchra & Geller (1982) and Maia et al. (1989) catalogues of galaxy groups are also estimated as ≈ 21ML and ≈ 100ML correspondingly. The influence of dark matter distributed in the common envelope on the dynamical properties and the merging rate in small galaxy groups are also considered. It is found that the significant dark matter makes motion of galaxies in groups more stocastic, increases the number of close double approaches between galaxies and increases slightly the merging rate. At the same time, the dark matter significantly decreases the number of long-lived temporary binary subsystems formed inside triplets.
Current Fundamental System Errors and Post-Hipparcos Utilization of Ground-Based Optical Instruments
Authors: Goncharov G.A.
Published: June 2019

Several modern ground-based optical instruments have indicated similar systematic differences of their catalogues with respect to the FK5. Thus, the FK5 apparently needs a correction of about 60·sin(6δ) mas for northern hemisphere declinations, other sine corrections of order 20 mas and some equator correction. These errors are the result of systematically erroneous proper motions due to position errors, particularly in old observations.
Solar EUV Photoelectric Observations from Skylab
Authors: Reeves E. M. , Foukal P. V. , Huber M. C. E. , Noyes R. W. , Schmahl E. J. , Timothy J. G. , Vernazza J. E. , Withbroe G. L.
Published: June 2019

Most of the atomic species originating in the solar atmosphere between the upper chromosphere and the corona have their strong characteristic wavelengths in the extreme ultraviolet region of the spectrum. A simple normal-incidence spectrometer system with solar blind detectors such as the Harvard instrument operating between approximately 250 Å and 1350 Å is ideally suited for observing in this most interesting range of the solar atmosphere where the temperature rises outward from 104 to 3 × 106 K. The temperature range represented by the various atomic and ionic species in the extreme ultraviolet is associated with many types of solar structure, prominences and filaments, the supergranulation cells and network, active regions and their associated loop structures and other features. Simultaneous observations in lines of different characteristic temperatures provide a three-dimensional probe of the solar atmosphere. In the instrument, the principal polychromatic position observes the Lyman continuum, Lα, C II, C III, O IV, O VI, and Mg x with seven detectors simultaneously from the same spatial image element, 5″ in size. Approximately 60 additional polychromatic positions are used routinely to carry out specific observing programs, for example, covering several lines of a given stage of ionization, observing lines or continuum from specific species of interest such as helium in prominences, comparing combinations of lines from a given ionic species such as O v where the relative intensities give a rather direct measurement of the density at a given temperature, or measuring differing positions in the Lyman continuum providing intensity measurements which can be interpreted in terms of the departure from ionization equilibrium.
Field Galaxies and Cluster Galaxies: Abundances of Morphological Types and Corresponding Luminosity Functions
Authors: Neyman Jerzy , Scott Elizabeth L.
Published: June 2019

With reference to theory published earlier, formulas are given for the estimation of (i) abundances of morphological types among field galaxies, (ii) of selection probabilities, and (iii) of ‘space luminosity functions’. Strictly, the theory applies to ‘homogeneous classes’ of galaxies. This term designates a category of galaxies, say C, so finely defined that the probability, say Φ(m | C), that a galaxy of category C will be included in the catalogue depends on its photographic apparent magnitude m and on nothing else. The practical use of the theory is illustrated on data in the HMS Catalogue. It appears that certain combinations of the Hubble morphological types satisfy the definition of a homogeneous class. Such, for example, is the case for combinations of ellipticals E0–E3 and, separately, of spirals Sc, Scp, SBc. However, the combination of these two categories is not a homogeneous class.

In order to validate the theory empirically, calculations were performed to predict the abundances of eight combinations of morphological types among cluster galaxies listed in the HMS Catalogue, each combination being treated as a distinct homogeneous class. Additional hypotheses underlying these calculations are: (a) abundances of morphological types, (b) luminosity functions of these types, and (c) selection probabilities for cluster galaxies coincide with those for field galaxies. A comparison with the observations, reaching the value of z = 0.07, is satisfactory. This tends to validate the combination of formulas (i), (ii), (iii) with the additional hypotheses (a), (b) and (c). Incidentally, the result tends to support the steady state cosmology.
Cosmological Synthesis of the Elements
Authors: Wagoner Robert V.
Published: June 2019

The results of improved calculations of the abundances of the nuclei produced in big-bang models of the early universe are presented. In addition to the standard model, other possible universes are considered, including the recent statistical bootstrap theory of Carlitz, Frautschi, and Nahm. Some conclusions which can be drawn about the nature of the early universe, depending upon whether the observed deuterium and helium are of galactic or cosmological origin, are presented.
Singularities in Cosmology
Authors: Penrose Roger
Published: June 2019

Singularities in space-time can be broadly divided into three classes: past-spacelike (in white holes or the big bang), timelike (naked singularities) and future-spacelike (in black holes or the final recollapse). In a closed Universe, if a simple restriction is made to eliminate timelike singularities, the inference may be drawn that the topology of the Universe is unchanging with time. Thermodynamical considerations lead one to infer that the final singularity of recollapse must differ markedly in structure from the initial big bang. This may plausibly be related to the existence of black holes and the presumed non-existence of white holes.
Creation of Particles in Cosmology
Authors: Zel'Dovich Ya. B.
Published: June 2019

The creation of particles is a process which can only be described by quantum field theory. The old classical theories dealing with indestructible particles are incompatible with particle creation. It was the discovery of the corpuscular nature of light (Einstein, 1905) and the prediction of antiparticles (Dirac, 1929) which demonstrated that particle creation was possible. The creation of particles may influence the cosmological equations through the energy-stress tensor of these particles. For physical cosmology the particles themselves are important. Therefore this report deals with a particular example of the impact of quantum mechanics on cosmological theory.
Baryon Symmetric Big Bang Cosmology
Authors: Omnès R. , Puget J. L.
Published: June 2019

In a big bang cosmology in which the Universe is initially filled with thermal radiation at a very high temperature the number of nucleon-antinucleon pairs decreases exponentially with temperature when the latter falls below a value such that kT ~ 1 GeV. To explain the observed ratio η = N/Nph ~ 10-9 where N is the average baryon density and Nph the photon density, nucleons and antinucleons must have been separated in the thermal radiation at a temperature greater than 30 MeV. A mechanism has been suggested which would lead to a phase transition in thermal radiation for kT > 300 MeV resulting in two phases with opposite non zero baryon number. The interaction between nucleons and antinucleons at intermediate energy is repulsive according to the mesonic theory of nuclear forces. This can be checked experimentally by measuring with enough precision the energy of X-rays emitted by the protonium atom and this experiment is now under way at CERN. Different models have been made to investigate their consequences and in each case a phase transition has been found above a temperature of the order of 300 MeV (Omnes, 1972; Aldrovandi and Caser, 1973; Cisneros, 1973).
Meudon Gravitational Radiation Detection Experiment
Authors: Bonazzola S. , Chevreton M. , Thierry-Mieg J
Published: June 2019

A description of Weber's type experiment of gravitational waves detection is given. Double and triple coincidences with Frascati and Munich groups were looked for with negative results. A capacitive passive method of detection has been presented. This method can improve the sensitivity by a factor of 30 when working at room temperature.
Gravitational Radiation by Ultrarelativistic Bodies
Authors: Westervelt Peter Jocelyn
Published: June 2019

I have shown (Westervelt, 1966) that ultrarelativistic bodies do not radiate gravitational waves in the forward direction. This work has been extended so as to apply to circular orbits. Even if low efficiency of generation precludes direct observation of gravitational waves, indirect evidence for their existence is available in a recent analysis (Westervelt, 1969) of Shapiro's fourth test of general relativity.
The Role of Gravitational Radiation in the Evolution of Dwarf Novae
Authors: Faulkner John
Published: June 2019

Mechanisms promoting mass transfer include (i) envelope instability or (ii) nuclear evolution of the red star and (iii) gravitational radiation of orbital angular momentum. Growing observational evidence against (i) is supported by recent theoretical work on the medium and long-term response of stellar radii to mass-loss (Eggleton, Faulkner and Webbink, in progress). Since (ii) is in most cases too slow a process, (iii) is left as the best surviving explanation.
A Class of Solutions of Einstein-Maxwell Equations with the Cosmological Constant
Authors: Plebański J. F.
Published: June 2019

Working in the signature (+ + + -) and units such that G = 1 = c, it was found a solution of Einstein-Maxwell equations with λ (without current and pseudo-current). In real coordinates xμ=(p, σ, q, τ) the solutions is:
(1)(2) where
(3) is pure imaginary; in (1) ‘d’ denotes the external differential]. Not all constants m0, n0, e0, g0, b, ∊, λ are physically significant: by re-scaling coordinates ∊ can be made equal to +1,0, or −1. The solution is of the type D: the double Debever-Penrose vectors
(4) have the common complex expansion Z = (q + ip)-1. Among C(a)'s only C(3) given by:
(5) is in general ≠0. The invariants of the electromagnetic field are:
(6)
A New Solution of the Einstein-Maxwell Equations for a System with Mass, Magnetic Moment, Charge, and Angular momentum
Authors: Witten Louis
Published: June 2019

A five parameter solution of the combined Einstein-Maxwell equations is given which describes a source containing mass, electric charge, magnetic dipole, higher multipole moments of all three kinds, and angular momentum. The solution is asymptotically flat and has a singular infinite red shift surface. Possible relevance of the solution to black hole physics is discussed.
The Dark Night-Sky Riddle, “Olbers's Paradox”
Authors: Harrison Edward
Published: June 2019

The riddle of cosmic darkness, nowadays known as Olbers's paradox, asks, “Why is the sky at night dark?” The riddle is almost as old as the Copernican revolution and has inspired important contributions to the development of astronomy and cosmology. It climaxes in the twentieth century with the realization that the sky is covered not by unseen stars but by the infrared gloom of the big bang.
The Ultraviolet Starlight in the Galaxy
Authors: Gondhalekar P. M.
Published: June 2019

The distribution of UV bright stars in the Galaxy is described. The integrated ultraviolet (UV) stellar radiation in the Galaxy is obtained from these data, and this flux of radiation is compared with observations and models of direct starlight in the Galaxy.
The Interstellar Radiation Field and Its Interaction with the Interstellar Matter
Authors: Mezger P. G.
Published: June 2019

Most stars emit most of their radiation in the wavelength range between the far ultraviolet (FUV) and near-infrared (IR). Eddington (1926) first estimated for the solar vicinity a mean radiation intensity of the interstellar radiation field (ISRF) equivalent to that of blackbody radiation of ~3 K but with a spectral distribution that can be approximated by ~10,000 K blackbody radiation diluted by a factor ≈ 10−14.
Stellar Photometry at the North Ecliptic Pole: The Contribution to Background Starlight
Authors: Leinert Ch. , Thiele U.
Published: June 2019

We performed UBVRI photometry in a 4.7° field of diameter centered on the North Ecliptic Pole, covering all 94 SAO stars and one planetary nebula. This represents the first step of an attempt to improve the knowledge of integrated starlight in this important viewing direction. The contribution of these bright stars to the integrated starlight is considerable (30–40%) and quite unevenly distributed. Therefore, surface photometry with large fields of view should be individually corrected for this contribution.
The Determination of Galactic Arms from the Brightness Distribution of Far Infrared Sources
Authors: Yi Tong , Jin Sun , Yuan Li Zhong
Published: June 2019

From the IRAS catalogue we selected 10,001 young infrared (IR) sources which lie within the galactic plane. Their IR flux integrated over ±5° in latitude shows maxima at galactic longitudes l = 80°, 60°, 50°, 35°, −27°, −54°, and −74°, which directions are interpreted as tangents to the spiral arms. The resulting spiral arm pattern is nearly identical with the arms derived from observations of O and B stars.
Faint Optical Line Emission from the Diffuse Interstellar Medium: Observations and Implications
Authors: Reynolds R. J.
Published: June 2019

Diffuse galactic Hα emission appears to cover the entire sky with an intensity that ranges from 3–12 R near the galactic equator to 0.25–0.8 R near the galactic poles. Observations of this H-recombination line and the forbidden lines, [S II] 6716 Å, [N II] 6583 Å, and [O III] 5007 Å, indicate that the emission originates from a low-density, 2–3 kpc thick layer of warm (~104 K), ionized interstellar gas that has an emission-line spectrum significantly different from that of the traditional, more localized H II regions. Along a line perpendicular to the galactic disk, the mean emission measure of this layer is 4.5 cm−6 pc, and the column density of the H+ is 2 × 1020 cm−2. The origin of this diffuse ionization is not yet clear; however, its existence requires the equivalent of about 14% of the total ionizing photon flux from O stars or nearly all of the power injected into the ISM by supernova. This optically emitting gas also may be a nonnegligible source of diffuse emission in the far ultraviolet (FUV) and infrared (IR).
High–Resolution V–Band Photometry of the Milky Way
Authors: Hoffmann B. , Kimeswenger S. , Schlosser W. , Schmidt-Kaler Th. , Seidensticker K. J.
Published: June 2019

High resolution (0.°25 × 0.°25) surface brightness distribution in V of the southern Milky Way over an area of 200° ≤ l ≤ 60° and of −30° ≤ b ≤ +30° was obtained by photographic plates, taken at La Silla, Chile, with the super-wide-angle camera with spherical mirror of the Astronomisches Institut der Ruhr-Universität Bochum (Schmidt-Kaler et al. 1983). Schmidt-Kaler et al. (1983) and Seidensticker, Schmidt-Kaler, and Schlosser (1982) carried out an analysis of these plates. However, these studies used only a fraction of the whole plate; interesting parts of the sky were chosen near the plate centers, thus minimizing various errors. The plates are now all scanned over the whole field of view with a PDS with a diaphragm of 50 × 50 μm = 0.°12 × 0.° 12 on the sky. The image size is 1201 × 1201 pixels per plate. The mean deviation during the scan time was less than 0.1%. Through the identification of about 50 stars and by using their l, b and x, y coordinates, the equations of the plates were solved with eight geometric parameters. The standard deviation of all parameters was less than 0.3 pixels on all plates.
High-Resolution B-Photometry of the Milky Way and Results on Galactic Structure
Authors: Kimeswenger S. , Schlosser W. , Seidensticker K. J. , Hoffmann B. , Schmidt-Kaler Th.
Published: June 2019

During the last two decades, many attempts were made to determine the global parameters of the Galaxy and to compare the Galaxy to other galaxies (Schmidt-Kaler and Schlosser 1973; de Vaucouleurs and Pence 1978; Gilmore 1984; van der Kruit 1986). While most of these investigations are based on star counts, a detailed overall study by surface photometry, because of the lack of homogeneous high-resolution data, is rare. The last attempt by van der Kruit (1986), based on Pioneer 10 data, suffered from low resolution. The great number of individual structures at low and even intermediate latitudes could not be recognized. Our work (B-band, Hoffmann et al. 1989, this volume; V-band, Schlosser, Schmidt-Kaler, and Schneider 1989; U-Band and R-band photometry, in preparation) provides this homogeneous high-resolution data.
Correlation of Infrared Emission with H I and CO Gas in the High Latitude Cloud Area L1642
Authors: Liljeström T. , Laureijs R.
Published: June 2019

The high-galactic-latitude cloud L1642 (l = 210.8°, b = −36.7°) is a suitable candidate to relate IR measurements with atomic and molecular data because it has a reasonable size with respect to the rather poor (IRAS) IR resolution, a moderate optical extinction and an isolated location in the direction towards the galactic anticenter. The exceptionally high galactic latitude of −36.7° implies that L1642 is some 60 pc below the galactic plane (if r ≈ 100 pc is adopted for its distance). L1642 is thus sufficiently far off the galactic plane to minimize the confusion by background gas and dust clouds.
Spectra of the Far–Ultraviolet Background Shortward of 1200 Å from Voyager 2
Authors: Holberg J. B.
Published: June 2019

Deep spectra of the far-ultraviolet sky background have been obtained by the Voyager 2 Ultraviolet Spectrometer (UVS) in the 500 to 1200 Å wavelength range. New diffuse galactic background results—particularly in the 900 to 1100 Å region—are presented, which extend the North Galactic Pole results of Holberg (1986) over a range of lower galactic latitudes. Twenty-four lines of sight are analyzed for the presence of residual diffuse continua. Typical upper limits of several hundred photons cm−2 s−1 Å−1 sr−1 are obtained for most lines of sight; however, a faint residual continuum is detected at several low-latitude locations. In Ophiuchus, a diffuse stellarlike continuum is attributed to scattering from interstellar dust.
The Extragalactic Diffuse Background in the Far Ultraviolet
Authors: Paresce Francesco
Published: June 2019

Due mainly to the minimal contaminating effects of zodiacal light and direct stellar emission, the far UV wavelength band from 912 to Ã 2000 å is ideally suited, in principle at least, for an accurate measurement of a diffuse background component due to sources outside our own galaxy. The cosmological significance of such radiation is of great current interest as it certainly includes the cumulative line-of-sight effect of galaxies and quasars and may include emission from both a lukewarm intergalactic medium and decaying massive particles such as neutrinos, photinos, etc. The radiation required to maintain the IGM at its known high ionization level should also, in any case, appear clearly in this band due to redshift and lookback time effects, thereby providing a crucial clue as to its presently obscure origins. Just how accurately this component can be measured in practice, however, clearly depends on how well we understand the probably dominant galactic component from which it must be disentangled in one way or another except, possibly, at the galactic poles. The residual emission there in this band is on the order of a few ×102 photons cm−2 s−1 sr−1 å−1, of which perhaps as many as 50 units are almost certainly due to galaxies since the small-scale spatial fluctuations corresponding to this flux almost exactly mimic those expected from the known spatial distribution of galaxies. The rest must come from a presently uncertain source, most likely a residual tenuous dust layer at the galactic poles. This latter possibility is at least consistent with recent IRAS results on the diffuse IR background at 100 μm and very sensitive HI, 21 cm measurements in these regions, but an extragalactic origin cannot be presently ruled out. Higher spatial and spectral resolution observations throughout the entire far UV range planned for the near future from orbiting platforms are expected to resolve this last but critically important issue.
The Extragalactic Radio Source Background
Authors: Wall J. V.
Published: June 2019

The background of discrete extragalactic radio sources is described from the point of view of its simplest properties: surface density and surface distribution. New considerations, particularly with regard to the latter, open the possibility of detecting Universal structure on many angular scales. At the same time, these considerations imply the need for greater sophistication in the interpretation of source counts and of the microwave background (MWBG) fluctuations.
Vacuum Ultraviolet Background Radiation Around the Virgo Cluster Region
Authors: Onaka Takashi
Published: June 2019

The vacuum ultraviolet (λeff = 156 nm and δλ ≅ 30 nm) observation around the Virgo Cluster region (l = 280°–320° and b = 60°–80°) was performed by the GUV experiment, a rocket-borne two-dimensional imager. The diffuse background radiation in the high galactic latitude region was obtained after subtraction of the contributions from airglow, stars, and galaxies in the field of view. A comparison with HI 21 cm radio observations indicates a weak correlation of the diffuse ultraviolet (UV) background radiation with HI column density, suggesting a low scattering efficiency of the interstellar dust grains in the far-UV and the existence of the isotropic component in the diffuse background radiation.
The Impact of CN Line Profile Measurements on the Cosmic Microwave Background Temperature
Authors: Kaiser M. E. , Wright E. L.
Published: June 2019

We present moderate to high signal-to-noise high-resolution (R ≈ 150,000–170,000) optical spectra toward ζ Oph. Gaussian fits to our data indicate a value of the line-width parameter b, of b = 1.4 ± 0.2 km s−1, along this line of sight. When CN is used as an indirect probe of the cosmic microwave background (CMB) temperature, the line profile is used to determine saturation corrections in the line. This affects column density calculations, which are reflected in the excitation temperature. Current measurements of the b-value along this line of sight range from 0.88 ± 0.02 km s−1 (Crane et al. 1986) to 1.3 ± 0.1 km s−1 (Hegyi, Traub, and Carleton 1972). The extreme range of these b-values yield saturation corrections to the CMB temperature that differ by 0.05 K, which is equal to the quoted precision of current measurements. Preliminary analysis of observations toward HD 29647 indicate that TCMB = 2.70 ± 0.14 K at 2.64 mm toward this line of sight.
The Spectrum Distortion of Relic Radiation in the Moment of Universe Recombination
Authors: Burdyuzha V. V. , Chekmesov A. N. , Lukash V. N. , Yakovlenko S. I.
Published: June 2019

Matsumoto et al. (1988) have reported a significant distortion in the spectrum of microwave background radiation in the submillimetre waveband 400-700 μ. This follows a rocket experiment by a team from Nagoya and Berkeley in February, 1987. This experiment has resulted in a series of papers which have attempted to interpret this excess (see Carr, 1988). This result may force us to revise the process of universe recombination and/or to resort to nonequilibrium processes. The distortion of the cosmic microwave background radiation (CMB) from Planck spectrum may necessarily arise because of the production of energetic quanta in the process of recombination which lead to retarding former and distortion of CMB both in the Wein region and the Rayleigh-Jeans region (Zeldovich, Kurt, and Sunyaev, 1969; Lumbarskii and Sunyaev, 1983).
The Vacuum Electromagnetic Field and the Energetics of the Intergalactic Medium
Authors: Rueda A.
Published: June 2019

The equilibrium distribution for a low-density infinite system of electromagnetically (EM) interacting particles placed in euclidean space in equilibrium with the Lorentz-invariant (LI) zero-point field (ZPF) is also LI with an energy density ρ(E)dE Ã E−1dE. This result follows semiclassically as well as quantum theoretically (QT). Such an idea is exploited to propose a means for energizing the intergalactic medium (IGM) and thus explain the X-ray background (XRB) as thermal bremsstrahlung (TB) of a 3 × 108 K thermally excited electron gas confirming observation (see, e.g., Marshall et al. 1980; Boldt 1987).
HUBE: The Hopkins Ultraviolet Background Experiment
Authors: Kimble Randy A. , Henry Richard C. , Paresce Francesco
Published: June 2019

The far-ultraviolet wavelength region between 1216 and ~2000 Å offers unusually favorable conditions for observing a variety of known or predicted diffuse emissions of both interstellar and extragalactic origin. We describe here a proposed instrument for studying those emissions, the Hopkins Ultraviolet Background Experiment (HUBE). HUBE consists of two compact, fast components: a broadband camera (1350-2000 Å) with 2′ resolution and an imaging spectrograph (1230-1800 Å) with 5 Å resolution. These complementary components will be utilized for both a sky survey and for sensitive deep pointings. As either a free-flying Scout-class satellite or as an attached payload on the Space Station, HUBE will make possible an investigation of unprecedented scope into the sources of the far ultraviolet background.
The Extragalactic Background Radiation — 1989
Authors: Longair Malcolm S.
Published: June 2019

This symposium has brought back many happy memories of the time 20 years ago when Rashid Sunyaev and I surveyed what was known about the extragalactic background radiation at that time. In one of our papers of 1969, we published a simple representation of the extragalactic background radiation spectrum, as it was known then (Figure 1). Extragalactic background radiation had been discovered in the radio, microwave, X- and γ-ray wavebands but only upper limits were available in the intervening wavebands which have been the principal concern of this symposium. It is remarkable that, over the last 20 years, although the observational techniques have developed dramatically and there have been enormous astrophysical advances, the wavebands between 1 mm and 1 nm have continued to be very difficult indeed for studies of the extragalactic background.
I.—Sketch of the History of the Frank Principality of the Morea
Authors: Tozer H. F.
Published: June 2019

Towards the end of the year 1204, the same in which the Latins captured Constantinople, Geoffrey Villehardouin, a French knight of a noble family in Champagne, and nephew of the Marshal of Romania of that name, whose chronicle has already been mentioned, was returning from Palestine, whither he had proceeded as a crusader, independently of the main expedition, on hearing of the successes of the Franks in overthrowing the Eastern Empire. Owing to stress of weather, however, he was forced to take refuge in the harbour of Modon (Methone) at the south-west angle of the Peloponnese, and while he was kept wind-bound at that place, entered into communication with one of the Messenian nobles, John Cantacuzenus, who was connected by marriage with the imperial family of Angelus, the successors of the Comneni, and conceived in connection with him a scheme for subduing this province of Greece. The circumstances of the country were in many ways favourable to such an undertaking, for the centralising policy of the Byzantine government, which feared nothing so much as revolt, had from time immemorial discouraged all organisation for purposes of self-defence on the part of the provincials, and that government itself had for the moment been destroyed. The prize, moreover, was a tempting one, for this portion of Greece had for several centuries been comparatively undisturbed by attacks from without and by internal struggles, and consequently was carefully cultivated and possessed a considerable amount of accumulated wealth. The alliance of Villehardouin with a native chieftain caused a prepossession among the Greek inhabitants in his favour, and this was afterwards strengthened, when they found that he was disposed to respect their privileges. In this way he with no great difficulty made himself master of the western coast of Messenia, the rich plain of Elis with its capital Andravída, and even the important city of Patras. But early in the following year John Cantacuzenus died, and his son Michael, discovering that the French leader was aiming merely at his own aggrandisement, broke off the alliance with him, and summoned the Greeks to arms in order to expel the invaders. Villehardouin perceived that he would soon be reduced to great straits owing to the smallness of the force at his disposal.
I.—The First Season's Work. Preliminary Narrative
Authors: Hogarth D. G.
Published: June 2019

The movement in favour of organised research in Cyprus which, originating in the latter part of the summer of 1887, led before the end of the year to the formation of a Fund directed by a Committee comprising all those who are most prominent in supporting the study of Classical Archaeology in this country, has been set forth already in circulars and reports, and needs only a brief allusion here in order to explain the causes and conditions of our subsequent work at Old Paphos and other sites in the winter and spring of this year. In the early mouths of 1887, Dr. F. H. H. Guillemard, the well-known traveller and ornithologist, spent a considerable time in Cyprus, and in the less known parts of the island saw and heard so much of continual discoveries, legitimate and illegitimate, that, on his return to England, he lost no time in pressing the desirability of sending an expedition on many who were interested in matters archaeological, with the result that the University of Cambridge took into consideration the question of making a grant from the Worts Travelling Bachelor's Fund for that purpose. The Society for the Promotion of Hellenic Studies was also sounded, and many circumstances conspired to induce their favourable consideration for such a proposal. Besides the valuable information communicated by Dr. Guillemard, it was known that the High Commissioner of Cyprus had resolved for sufficient reasons, which need not be detailed here, to discountenance in future all private exploration in the island, but at the same time had declared his willingness to help any work organised and conducted by a recognised scientific body: it resulted therefore that, unless such bodies undertook the task, no one would attempt to solve the many problems connected with the island for some years to come.
Geological Considerations
Authors: Jennings Jesse D.
Published: June 2019

If the data recovered at the Wendover caves are to be fully evaluated, the student must turn to the geologic and climatic events of the late Pleistocene and the Recent geologic epochs. Some of the cave data may even contribute to the study of the sequence and duration of climatic fluctuations within late Pleistocene and Recent times.

The archeological interest in geologic/climatic matters develops for various reasons. First is the matter of chronology. By means of radiocarbon dating we know that man visited Danger Cave about 9000 B.C. It is necessary to correlate these deposits with already recognized geologic and climatic events. Fortunately for this purpose a fairly specific calendar of geological time exists. If the cave deposits could be correlated with natural events this correlation automatically provides, at very least, estimates of the time of occurrence of the natural cave deposits. Another interest the archeologist has in a valid geologic, and hence climatic, correlation lies in the insight he may gain into the environmental circumstances which man faced at any given time during his conquest of the Americas.
Spin Correlation in Binary Systems
Authors: Farbiash N. , Steinitz R.
Published: June 2019

We examine the correlation of projected rotational velocities in binary systems. It is an extension of previous work (Steinitz and Pyper, 1970; Levato, 1974). An enlarged data basis and new tests enable us to conclude that there is indeed correlation between the projected rotational velocities of components of binaries. In fact we suggest that spins are already correlated.
Observations of the Triple Star ETA Virginis with a Long Baseline Optical Interferometer
Authors: Hummel C.A.
Published: June 2019

We observed the hierarchical triple star Eta Virginis with the Navy Prototype Optical Interferometer and present the first images resolving all three components. The stars in the close pair have a separation between 4 and 9 milliarcseconds. The orbital motions of the stars were followed during the winter and spring of 2002. Preliminary, astrometrically determined orbits of the two components in the close pair by reference to the tertiary were derived, thus enabling the estimation of the mass ratio (1.27) of the components in the close pair. We also determined the relative orbital inclination to be 31 degrees. We describe the model-fitting process to interferometrie and spectroscopic data, and discuss some astrophysical component parameters.
Increased Multiplicity of 77 Cygni, V815 Herculis, and HD 140122
Authors: Fekel Francis C.
Published: June 2019

High-dispersion spectroscopic observations of 77 Cygni, V815 Herculis, and HD 140122 have resulted in the detection of at least one additional component in each system. The newly identified component of 77 Cyg has a period of 35.48 days. V815 Her is a triple system with periods of 1.810 and 2300 days or 6.3 yr. The two visual binary components of HD 140122 are short-period spectroscopic binaries with periods of 10.879 and 15.770 days.
The Distribution of Separations of Wide Binaries of Different Ages
Authors: Poveda Arcadio , Allen Christine
Published: June 2019

For the purpose of understanding how the distribution of major semiaxes of double and multiple stars has evolved from the earliest ages up to the ages of the oldest systems, we have studied a number of different groups of such systems. We review and expand our previous work on the following groups of stars: (a) The wide binaries in the IDS; (b) Luyten’s common proper motion pairs (the LDS catalogue), (c) Our catalogue of nearby wide binaries divided into two groups: the youngest and the oldest; (d) The common proper motion pairs in the Orion Nebula cluster; (e) Our sample of high velocity, low metallicity binaries that represents a population of very old systems. From the very young binaries (Orion Nebula Cluster) to the oldest (thick disk and halo), all groups show a distribution of major semiaxes following Oepik, i.e., f(a) da ∝ da/a (where a is the major semiaxis), valid over an interval of a between 60 AU and am(t), am(t) being a maximum semiaxis which depends on the age of the binaries as well as on the number density and velocities of the massive objects they encounter as they travel in the Galaxy. Strong gravitational encounters in recently formed multiple systems were found to produce an Oepik distribution, which at small separations (a ≤ 40 − 60 AU) gets truncated by circumstellar disks and close binaries, and at large separations gets depleted by encounters with massive objects.
Multiple Stars with Both Inner and Outer Orbits Observed Spectroscopically
Authors: Griffin R.F.
Published: June 2019

Some progress has been made towards determining the long-period outer orbits of certain spectroscopic multiple stars.
Photometry of the δ Scuti Star DG Leo: Preliminary Results
Authors: Lampens P. , Garrido R. , Parrao L. , Peña J.H. , Arentoft T. , Frémat Y.
Published: June 2019

New uvby photoelectric photometry has been acquired for the triple star DG Leo at two different observatories equipped with analogous instrumentation. A preliminary period analysis indicates the presence of at least 3 close δ Scuti frequencies (10-12 c/d, 3-6 mmag) and a slow variation. This slow variation fits quite well with half the orbital period of the spectroscopic binary; the noise level in the amplitude spectrum is only 3–4 mmag (after prewhitening).
The Double-Lined Spectroscopic Binary HR 6046
Authors: Scarfe C.D. , Griffin R.F. , Griffin R.E.M.
Published: June 2019

HR 6046 has long been known as a single-lined binary with a late-K-giant primary star. The long period of just over six years and the large mass function led to several, so far unsuccessful, attempts to resolve the system interferometrically. However, we have detected the secondary spectroscopically, and present here the spectroscopic orbital elements. The secondary is nearly as massive as the primary, despite being much fainter. Comparison with late-type standard spectra suggests that it is also an evolved star.
Orbital Motions in Binary Protostellar Systems
Authors: Rodríguez L.F.
Published: June 2019

Using high-resolution (~ 01), multi-epoch Very Large Array observations, we have detected orbital motions in several low-luminosity protobinary systems in the Taurus and ρ Ophiuchus molecular complexes. The masses obtained from Kepler’s third law are of the order of 0.5 to 2 M⊙, as expected for such low-mass protostars. The relatively large bolometric luminosities of these young systems corroborates the notion that protostars obtain most of their luminosity from accretion and not from nuclear reactions. In addition, in one of the sources studied (a multiple system in Taurus), a low-mass young star has shown a drastic change in its orbit after a close approach with another component of the system, presumed to be a double star. The large proper motion achieved by this low mass protostar (20 km s−1), suggests an ejection from the system.
What Causes the Low Binary Frequency in the Orion Nebula Cluster?
Authors: Köhler R.
Published: June 2019

We report on the results of a binary survey in the outer parts of the Orion Nebula Cluster, 0.7 to 2 pc from the cluster center. The results should help to decide if the binary formation rate was lower in Orion than in Taurus-Auriga, or if many binaries formed initially, but were destroyed in close stellar encounters. We find that the binary frequency of low-mass stars does not depend on the distance to the cluster center. The companion star frequency of intermediate- to high-mass stars shows a trend to decrease with cluster radius, but the statistical significance of this trend is rather weak.
Young Stars far from the Galactic Plane: Runaways from Clusters
Authors: Allen Christine , Kinman T.D.
Published: June 2019

Quite recently, a significant number of OB stars far from the galactic plane have been found, situated at z- distances ranging from several hundreds of pc to several kpc. The short lifetimes of these stars pose problems for their interpretation in terms of the standard picture of star formation. Different mechanisms have been put forward to explain the existence of these stars, either within the conventional view, or postulating star formation in the galactic halo itself. These mechanisms range from arguing that they are misidentified evolved or abnormal stars, to postulating powerful ejection mechanisms for young disk stars; in situ formation also admits several variants. We have collected from the literature a list of young stars far from the plane, for which the evidence of youth seems convincing. We discuss two possible formation mechanisms for these stars: ejection from the plane as the result of dynamical evolution of small clusters (Poveda et al. 1967) and in situ formation, via induced shocks created by spiral density waves (Martos et al. 1999). We compute galactic orbits for these stars, and identify the stars that could be explained by one or the other mechanism. We find that about 90 percent of the stars can be accounted for by the cluster ejection mechanism, that is, they can be regarded as runaway stars in the galactic halo.
Formation and Evolution of Hierarchical Systems
Authors: Aarseth Sverre J.
Published: June 2019

Initial distributions of primordial binaries used in realisticN-body simulations give rise to bound subsystems of different multiplicity. An examination of the formation process shows that the most compact triples arise via binary-binary collisions, whereas higher-order systems have diverse origins. Low formation rates are compensated by long life-times, leading to a significant population building up. Being fairly energetic, the outer orbit tends to shrink by further encounters. In addition, external perturbations also modify the eccentricity and may create conditions for instability. Onecharacteristic outcome is internal disruption by the sling-shot mechanism. Such interactions are often sufficiently energetic to produce high-velocityescapers and it is not uncommon for triples and quadruples to be ejected. For high inclinations, the eccentricity growth induced by the Kozai effect may lead to significant shrinkage of the inner binary orbit by tidal circularization. If some of the components were spit into a dynamically inactive ultra-hard binary, the hierarchies would be attributed an even higher multiplicity. One implication of these results is that a proportion of multiple systems observed in the field may have been formed in a dynamical environment.
The Interaction of Binary Systems with Accretion Disks
Authors: Ortega-Rodríguez Manuel
Published: June 2019

We study the (time) fluctuations in the outgoing radiation of accretion disks in binary systems in order to obtain properties of those systems (via comparison with observations), such as the angular momentum of the compact star within the disk. The effects of the companion star are discussed, and a prediction is made on the frequency of the outgoing (modulated) X-ray radiation.
Guieloa: Adaptive Optics System for the 2.1-M SPM UNAM Telescope
Authors: Cuevas S. , Iriarte A. , Martínez L.A. , Garfias F. , Sánchez L. , Chapa O. , Ruelas R.A.
Published: June 2019

Guieloa is the adaptive optics system project for the 2.1-m SPM telescope. This is a 19 sub-apertures curvature-type system. It corrects 8 Zernike terms. Guieloa is very similar to PUEO, the CFHT adaptive optics system and compensates the atmospheric turbulence from the R band to the K band. Among the planned applications of Guieloa are the study of OB binary systems, the detection of close binary stars, and the study of disks, jets and other phenomena associated with young stars.