bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dusty KING Spheres
Authors: Fröhlich H.‐E. 
Published: July 2007

AbstractIn order to determine the quantitative influence of small amounts of dust on the luminosity profile of spherical galaxies, we represent an elliptical galaxy by a KING sphere filled with dust. The density of dust particles is assumed to be related to the density of stars according to a simple power law. Assuming that the observed central reddenings in NGC 4874 and NGC 4889 are really caused by dust, we estimate the optical depths in the centres of both galaxies to be about 0.75.
The Interstellar 2200 Å Band: A Catalogue of Equivalent Widths (Mitteilungen der Universitäts‐Sternwarte zu Jena Nr. 151)
Authors: Gürtler J. , Schielicke R. , Dorschner J. , Friedemann C. 
Published: July 2007

AbstractUsing the data of the Ultraviolet Bright‐Star Spectrophotometric Catalogue, the equivalent width of the interstellar absorption band at 2200 Å is derived for 422 stars. A preliminary statistical analysis confirms the good correlation between the equivalent width of the 2200 Å band and the colour excess. The wavelength position of the band centre seems to vary to a small extent.
Einfluß verbesserter Deklinationswerte auf die PZT‐Breiten‐bestimmungen in Potsdam (Mitteilungen des Zentralinstituts für Physik der Erde Nr. 1027)
Authors: Meinig M. 
Published: July 2007

AbstractDie Ergebnisse der Breitenbestimmungen mit dem PZT in Potsdam in den Jahren 1972–78 wurden verwendet, um die Deklination der beobachteten Sterne zu verbessern. Mit den berechneten Deklinationskorrektionen wurden die Breitenbestimmungen auf das System des neuen Katalogs umgerechnet. Die erhaltenen Ergebnisse zeigen eine wesentlich bessere Übereinstimmung und eine größere Stabilität in bezug auf das BIH‐System als die Ergebnisse im System des bisher verwendeten Sternkatalogs.
New Dwarf Galaxies in the M81/M82 Group
Authors: Börngen F. , Karachentseva V. E. 
Published: July 2007

AbstractA survey for dwarf galaxies (Sculptor‐type dwarfs) was carried out in the M81/M82 group of galaxies in an area of about 195 sq. degrees by means of Tautenburg 52‐in. Schmidt plates. Eight new faint dwarf galaxies were discovered. Coordinates, linear and absolute dimensions as well as finding charts are given. Results of the photometry will be published in a second article.
Inhomogeneous Cosmological Models Containing Homogeneous Inner Hypersurface Geometry. Changes of the BIANCHI Type.
Authors: Schmidt H.‐J. 
Published: July 2007

AbstractThere are investigated such cosmological models which instead of the usual spatial homogeneity property only fulfil the condition that in a certain synchronized system of reference all spacelike sections t = const. are homogeneous manifolds. This allows time‐dependent changes of the BIANCHI type. Discussing differential‐geometrical theorems it is shown which of them are permitted. Besides the trivial case of changing into type I there exist some possible changes between other types. However, physical reasons like energy inequalities partially exclude them.
Application of a Computer Controlled Intensity Registering Procedure to the Spectral Region at 4430 Å
Authors: Lehmann H. 
Published: July 2007

AbstractA computer controlled measuring procedure is presented ascertaining intensity courses. The procedure is capable for measurement and storage of the transmittance of photographic spectrograms and for the determination of residual intensities derived from a mean local continum. Residual intensity courses obtained from several spectrograms can be superimposed and correlated with wavelength scale.The method was applied to eight weakly or not reddened early type stars in order to obtain data on atomic lines in the central part of the diffuse interstellar line at 4430 Å. The results show the general influence of the stellar portion on the central depth and equivalent width of the whole diffuse feature.
Zur kosmologischen Testung des Machschen Prinzips
Authors: Treder H.‐J. 
Published: July 2007

AbstractThe Machian models of isotropic expanding universes according to the “inertia‐free” gravo‐dynamics imply the equationsbetween the instantan valuesH0andq0of the HUBBLEparameterH, the accelerationq, and the matter density o. Therefore, in Machian universes with linear expansionq0= 0 the energy integralE= ‐1/2ϵc2is zero and the matter density becomes (withH02R02=c2/3)(f0the Newtonian gravitational constant). This is the critical density in general relativistic cosmology.
Membership of faint stars in the globular cluster M3
Authors: Scholz R.‐D. , Kharchenko N. V. 
Published: July 2007

AbstractA proper motion study from Tautenburg Schmidt plates is presented for the globular cluster M3 and its vicinity. The plates were scanned with the Automated Photographic Measuring (APM) system in Cambridge (UK). A photographic B,V photometry and star counts on the deepest plates were carried out. With a limiting magnitude of about B = 21.4 proper motions with an accuracy from 2 to 3 mas/yr have been obtained for stars with B 19. The proper motions were determined using a stepwise regression method with 3rd order polynomials in the plate‐to‐plate solutions with about 2000 reference galaxies. The results which were corrected for systematic errors dependent on position and magnitude of the stars were used for the determination of membership probabilities. We also looked for possible internal motions of M3.
Elliptic‐type motion in Fock's gravitational field
Authors: Mioc V. 
Published: July 2007

AbstractThe elliptic‐type motion in the gravitational field found by Fock as exact solution of Einstein's vacuum equations in the case of spherical symmetry (Solution called here Fock's gravitational field) is studied by means of a classic method based on the perturbation theory. Regarding the deviations of the orbit from a Kepleian orbit as perturbations, the first and second order variations of the Keplerian orbital elements over one nodal period as well as those of the nodal period itself are determined.
Cosmological constant as integration constant
Authors: Treder H.‐J. 
Published: July 2007

AbstractEinstein's field theory of elementary particles (Einstein 1919) yields black holes with a mass M ˜ G−1 Λ−1/2c2 and a charge Q ˜ G−1/2λ−1/2c2, their curvatu re radius is Λ−1/2. Here 4Λ is an integration constant of Einstein's ‘trace‐less’ gravitation equations.The choice λ = G−1h−1c3 for this constant defines Planckions and implies “strong gravity”. The choice λ = λ = 3Hinf2c−2 (where Hinf means the Hubble parameter of a final de Sitter cosmos) involves “weak gravity” and describes an electro‐vac spherical universe.
The evolutionary state of magnetic Ap stars
Authors: Hubrig S. , Mathys G. 
Published: July 2007

AbstractThe characteristics of two stars, 25 Sex and HD 21699, as additional candidates for the sample of magnetic stars belonging to superclusters, are discussed. For 25 Sex, which was already accepted as a probable member of the Hyades supercluster in a previous study, arguments supporting the view that this star indeed is a magnetic star are presented. In the case of HD 21699, the radial velocity derived from our observations is not inconsistent with membership. But from the determinations of its proper motion found in the literature, this star cannot be regarded as a probable member of the α Per cluster. On the basis of recent evolutionary models, all the well established Ap cluster members appear to be close to the end of their main‐sequence life. This suggests that A stars possibly become magnetic at the end of core hydrogen burning.
Remarks on the period variation of HS Herculis and SW Cygni
Authors: Todoran I. , Agerer F. 
Published: July 2007

AbstractIn order to get a satisfactory understanding of the periodic variation of the orbital period in the binary system HS Herculis, the study of this problem is resumed. Using recently observed primary and secondary minima, it is evident that after 1955 (E > ‐2000) the corresponding O – C diagram reflects the effect of apsidal motion. Any assumption on the presence of a third body is rejected, at least as long as the current aspect of the O–C diagram is concerned. For the interpretation of the sinusoidal period variation of the semi‐detached system SW Cygni, 130 primary minima were compiled form the literature. Though it is considered as very likely that this variation of the period is primarily caused by apsidal motion, the hypothesis of a third body is analysed too. Further precise photometric and spectroscopic observations are recommended.
Iron abundance and microturbulence in Arcturus, Canopus, α Cen A, and Sun from FeI and FeII lines
Authors: Gadun A. S. 
Published: July 2007

AbstractThe iron abundance and microturbulent velocities in Arcturus, Canopus, and α CenA have been determined from Fel and Fell lines relative to the Sun. α CenA is found to have an enhanced iron abundance, while Canopus and Arcturus are found to have a deficiency of iron. The behaviour of the determined microturbulent velocities is discussed.
Asteroids observed at the GPO, La Silla
Authors: Debehogne H. , Andreev G. V. , Shefer V. A. 
Published: July 2007

AbstractContinuing the observational programme, which was started in 1976 at the European Southern Observatory (ESO), La Silla, by Debehogne a lot of new photographic plates was obtained during February‐March in 1989.These plates are used for the determination of positions of asteroids selected by „Ephemerides of Minor Planets for 1989”︁, edited by the Institute of Theoretical Astronomy of Leningrad (ITA) in 1988. They permit also discoveries of new celestial bodies as well as reidentifications of lost or badly observed asteroids during the last years. For the part treated here, the examination of the plates has revealed nine asteroids not mentioned in the Russian Ephemerides or in the disquettes as fournished by the Minor Planet Centre (MPC) of SAO. Seven were present in the ITA source.
The problem of the sighting line stabilization for axial meridian circles
Authors: Lazorenko P. F. , Sergeev A. V. 
Published: July 2007

AbstractThe paper deals with the method based on treating the axial meridian circle and a long‐focus light mark in the prime vertical as a single virtual instrument that has properties of meridian circle. A horizontal axis, a sighting line, and a micrometer cross‐wire of the instrument are created by optical means. The key function here is performed by the light mark that ensures a reference direction used for formation of instrumental principal planes and directions. Stability of instrumental azimuth, inclination, and collimation is expected to be about ±0.″01. Besides, an accuracy of observations is not affected by any temperature and weight deformations of telescope mechanics. Owing to the last circumstance, the design is cheap and the telescope aperture may be increased significantly, to about 1m. An estimate of accuracy of observations depends on the adopted model of image motion, and for sites with excellent seeing and bright stars is ±0.″03 to ±0.″05 (rms).
Synthetic luminosity functions of galaxies in different environments
Authors: Böhm P. , Schmidt K.‐H. 
Published: July 2007

AbstractAdopting luminosity functions of various morphological types of galaxies and galaxy populations for different environments characterized by the density, the overall differential and integrated luminosity functions of Hubble mix in different dense regions have been obtained. The calculated overall luminosity functions show a weak dependence on the density. Although there is a satisfactory agreement between the calculated overall luminosity functions and the observed distributions of samples of corresponding densities, the observed data are too uncertain in order to confirm the expected density dependence.
Photoelectric observations in a wide‐field area around the Praesepe cluster
Authors: Grankin K. N. , Ibragimov M. A. , Tselishchev I. E. 
Published: July 2007

AbstractThe PPM catalogue numbers, photoelectric magnitudes V, color‐indexes U – B, B – V, V – R and rms errors of their determinations for 51 stars of the secondary wide‐angle photoelectric standard are published. The catalogue accuracy of quantities mentioned above is 0.007, 0.015, 0.006, 0.006 mag, respectively. A list of ten stars which are probably variable is published.
The 10‐year time delay of the solar cycle luminosity modulation of the Sun behind the solar cycle magnetic oscillation
Authors: Yoshimura Hirokazu 
Published: July 2007

AbstractWe found an evidence that the solar cycle luminosity modulation of the Sun deduced from the total irradiance modulation which was measured by the Earth Radiation Budget (ERB) experiment on board of Nimbus 7 from November 16, 1978 to December 13, 1993 was not in phase with the solar cycle magnetic oscillation when we used the sunspot relative number as its index. The modulation was delayed in time behind the solar cycle magnetic oscillation by an amount of about 10.3 years on the order of length of one solar cycle. In order to quantitatively evaluate the correlation between the two quantities, we devised a method to extract characteristics which were proper to a particular solar cycle by defining a new index of the correlation called multiplied correlation index (MCI). We found that the characteristics of the ERB data time profile between solar cycles 21 and 22 were more similar to those of the solar cycle magnetic oscillation between solar cycles 20 and 21 than those between solar cycles 21 and 22 and thus the time profile of the luminosity modulation from the maximum phase of solar cycle 21 to the declining phase of the solar cycle 22 corresponded to the solar cycle magnetic oscillation from the maximum phase of solar cycle 20 to the declining phase of solar cycle 21. We interpret this phenomenon as an evidence that main features of the modulation is not caused by dark sunspots and bright faculae and plages on the surface of the Sun that should instantaneously affect the luminosity modulation but is caused by time‐delayed modulation of global convection by the Lorentz force of the magnetic field of the solar cycle. The delay time of about 10.3 years is the time needed for the force to modify the flows of the convection and to modulate heat flow. Thus the delay time is a function of the strength of the magnetic field oscillation of the solar cycle which is represented by amplitude of the solar cycle. Accordingly, the delay time for other time intervals of the solar cycle magnetic oscillation with different amplitudes can be different from 10.3 years for the interval of the present analysis.
Beobachtungen Kleiner Planeten. XIV
Authors: Börngen F. 
Published: July 2007

AbstractA summary is given about the Minor Planet survey performed in 1993 on Tautenburg Schmidt plates. 392 asteroids were observed and 1462 positions are calculated for them. These are 297 asteroids with provisional designations (217 of them have new designations) and 95 numbered objects. Ten new designations originate from the KSO‐ARI‐Survey IV. Tautenburg observations could give a tribute to 50 planets numbered in the period of this report. Six Tautenburg asteroids have been numbered (Tab. 3).
Observations of variable stars with the R Coronae Borealis phenomenon and other unique objects
Authors: Rosenbush A. E. 
Published: July 2007

AbstractThe results of photometry and polarimetry of the R Coronae Borealis type stars and other interesting objects are given. The observation of the former objects are obtained at the light maximum or at a brightness lower by 2‐3 mag. The polarization of R CrB stars at light maximum has interstellar origin. The absolute magnitude of V 854 Cen is estimated to Msvw = −3m, and for Y Mus it is Mv > −3m.7. ρ Cas has a variable polarization and is probably a giant (Mv ≅ 0m) rather than a supergiant. Many early stars in its surroundings are photometrically and polarimetrically variable. The protoplanetary star BD −0°3679 has a polarization with the Rayleigh component.
Photometric survey near the Main Galactic Meridian: 1. Photoelectric stellar magnitudes and colours in the UBVR system
Authors: Andruk V. , Kharchenko N. , Schilbach E. , Scholz R.‐D. 
Published: July 2007

AbstractA catalogue of photoelectric stellar magnitudes and colours in the UBVR Johnson system in 47 sky areas with galaxies near the Main Galactic Meridian is presented. The catalogue includes 1141 stars within the V magnitude interval 4m.5–15m.5. The rms errors are ±0.014, ±0.026, ±0.012, ±0.016 mag for stellar magnitudes V and colours (U – B),(B – V),(V – R), respectively. The catalogue contains accurate equatorial coordinates (α, δ)1950.0, too.
uvbyß photometry of the components of Trapezium‐type multiple systems
Authors: Salukvadze G. N. , Javakhishvili G. Sh. 
Published: July 2007

AbstractThe present paper deals with the results of photoelectric observations of 70 components of 19 Trapezium‐type multiple systems in Strömgren and Crawford six‐colour photometric systems. The trapezia were selected from the Abastumani Catalogue. Observations were carried out with the automatic and computer controlled 125‐cm Ritchy‐Cretien telescope (F = 1590 cm) at the Abastumani Astrophysical Observatory. The results are listed in Table 1. In conformity with the Strömgren criteria the components were ascribed to B, AF and A spectral classes (Table 2). Absolute magnitudes of the components were determined and effective temperatures and gravitational forces on the stellar surface calculated.
About possible geophysical causes of the decade fluctuations in the length of day
Authors: Greiner‐Mai H. 
Published: July 2007

AbstractFluctuations in the length of day (Δlod) can be caused by temporal variations of the inertia tensor described by the excitation function and by disturbances of the torque balance between core and mantle. Recent models of the atmospheric excitation of the variations of the lod certainly failed with respect to longer periods (e.g., at about 70 years), but seem to be responsible for the annual period, the 22 years period and for a part of the nearly 30 years period. So, another geophysical phenomenon is needed which is responsible for the remaining part of unexplained lod variations. Previous studies of the geomagnetic core‐mantle coupling were re‐examined using lod values from which atmospherically excited parts were removed. The remaining part of the 30 years period could be explained by core‐mantle coupling. Additionally, the torque blance was realized by assuming lower values of the electrical conductivity at the bottom of the mantle. It was concluded that the consideration of geophysical processes within atmosphere and hydrosphere will be important for future refinements of the core‐mantle coupling models of the decade fluctuations in the lod.
Investigation of PPM catalogue accuracy
Authors: Kharchenko I. N. , Pakulyak L. , Molotaj O. , Tel'nyuk‐Adamchuk V. 
Published: July 2007

AbstractThe PPM catalogue contains the most complete and accurate information concerning positions, proper motions and some astrophysical data for practically all stars (about 379000) down to 10m‐11m over the whole sky. The systems and rms errors of the PPm positions, proper motions, stellar magnitudes and spectral classification are studied by comparison with catalogues of stellar characteristics and on the basis of the PPM data itself. The residual errors of stellar data in the PPM catalogue are small and/or they can be determined and eliminated.
The Cosmological Problem as Initial Value Problem on the Observer's Past Light Cone: Observations
Authors: Dautcourt G. 
Published: July 2007

AbstractIn a previous paper it was shown how cosmological models can be characterized by few initial data on the observer's past light cone. Part of the inner geometry of the past cone as well as some matter variables taken on the cone (in the simplest case the velocity and density of a cosmological fluid) determine a world model uniquely within the past light cone. Since the initial data to some degree enter the relations between observable quantities such as redshift, luminosity, angular diameter, number counts, distortion parameters and background radiation intensity, it might be possible to determine the required initial data from observations. This problem is discussed in the present article for some observable relatios involving the quantities just mentioned.
On Caustic Diffraction of Scalar Matter in General Relativity
Authors: Paul H. G. 
Published: July 2007

AbstractThe intensity behaviour of gravitationally focused (de‐focused) scalar massive matter φ(xϱ) generating the focusing (defocusing) spacetime via Einstein's equation is investigated in different collapse regions (weak collapse, strong and weak dynamical collapse domain in the region of strong collapse). The dynamical collapse of, in general, non‐geodesic moving matter φ is braked by de‐focusing effects inherent in field theoretic description. If the intensity is greater than definite bounds at significant states, the collapsing matter φ cannot be stopped by de‐focusing caustic diffraction before singular states of matter φ and curvature Rμv are reached; this singularities could be related to the notion physical singularity.
An Upper Bound on Neutron Star Masses
Authors: Kämpfer B. 
Published: July 2007

AbstractWe derive an upper bound on neutron star masses by using model equations of state in the nuclear matter density region and the causality limited equation of state in the ultradense region. Supposing that the model equations of state describe neutron star matter at nuclear matter density correctly we find as bound 3.75 M⊙. For large fiducial densities one gets a maximum mass which is above a previous estimate.
Verbesserung der Sternörter des Potsdamer PZT‐Katalogs (Mitteilungen des Zentralinstituts für Physik der Erde Nr. 1220)
Authors: Meinig M. 
Published: July 2007

AbstractAus den Ergebnissen der Zeit‐ und Breitenbestimmungen mit dem PZT in den Jahren 1972–78 wurden neue Rektaszensions‐ und Deklinationskorrektionen für den Potsdamer PZT‐Katalog berechnet. Die korrigierten Sternörter bilden den Katalog PZT 80, der im Anhang gegeben ist. Der Vergleich mit dem vorher verwendeten Katalog PZT 74 zeigt eine Qualitätsverbesserung für den neuen Katalog. Auch die systematischen Abweichungen in bezug auf den Katalog der nördlichen PZT‐Sterne NPZT 74 sind vor allem für die Deklinationen kleiner als beim alten Katalog.
The Diameter of (106) Dione
Authors: Kristensen L. K. 
Published: July 2007

AbstractThe mean diameter D = 147 ± 3 km of (106) Dione is derived from visual observations in Denmark, Germany and the Netherlands of the occultation of AGK3 + 25°0989 on 1983 January 19. Photoelectric magnitudes are: B(1, 2°.4) = 8m.51 ± 0m.06 and B – V = 0m.65 ± 0m.07. The visual albedo is pv = .064. Constraints on the axis of rotation are derived from the observed elliptical contour.
Oscillatory motions in the sun corresponding to the solar cycle
Authors: Tuominen I. , Virtanen H. 
Published: July 2007

AbstractThe mean velocities derived from the proper motions of sunspot groups show a similar behaviour as the torsional oscillation found by HOWARD and LABONTE (1980), and the mean velocities have also a meridional component which changes according to the solar cycle. Calculation of the Lorentz force from a kinematical mean‐field dynamo shows that both of these components are a natural consequence of an α–ω dynamo acting in the solar convection zone.