bluuebunny/crossref_metadata_2025_split huggingface dataset:
EINSTEIN and MICHELSON The Context of Discovery and the Context of Justification
Authors: Stachel J. 
Published: July 2007

AbstractThe philosopher of science is not much intersted in the thought processes which lead to scientific discoveries; he looks for a logical analysis of the completed theory, including the relationships establishing its validity. That is, he is not interested in the context of discovery, but in the context of justification … it appears amazing to what extent the logical analysis of relativity coincides with the original interpretation by its author, as far as it can be constructed from the scanty remarks in EINSTEIN's publications. In contradistinction to some developments in quantum theory, the logical schema of the theory of relativity corresponds surprisingly with the program which controlled its discovery.
Photometric catalogue of Shakhbazian compact groups of galaxies. IV.
Authors: Stoll D. , Tiersch H. , Oleak H. , Macgillivray H. T. 
Published: July 2007

AbstractThe fourth part of the photometric catalogue of Shakhbazian compact groups of galaxies contains optical and geometrical properties of another 26 groups (Shkh 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 357). As in the previous papers photometric data were obtained from the COSMOS/UKST catalogue of the Southern sky with δ ± +2°30'. The survey of compact galaxy groups by Shakhbazian, Petrosian, Baier, and Tiersch is a basis for studying physical properties of such groups.
Non‐rigid rotation of solar spicules
Authors: Pishkalo M. I. 
Published: July 2007

AbstractHα profiles of chromospheric spicules computed for a variety of rotational behavior are compared with an observed profile, which was derived by averaging 11 Hα profiles taken near times of maximum spicule intensity. If turbulent velocity is small or equals zero, calculated profiles are in good agreement with the observed one under the conditions that rotation is non‐rigid (faster rotation further away from the axis of the spicule) and the source function decreases in the direction from the spicule axis to the periphery. The comparison of calculated and observed tilts of spicule spectra relative to the direction of dispersion seems to corraborate the non‐rigid character of spicular rotation.
Proper motions in the field of the globular cluster NGC 6934
Authors: Tucholke H.‐J. 
Published: July 2007

AbstractWe measured relative proper motions with a typical accuracy of 1.0 milliarcsec/year (mas/a) for 2000 stars in a 1°4 × 1°4 field around the low‐latitude globular cluster NGC 6934. Four plates taken with the Bonn double refractor, spanning an epoch difference of 62 years, were digitized completely. Within the tidal radius of the cluster, we find 106 stars with proper motion errors less than 5 mas/a. Membership probalilities are computed taking into account the individual proper motion errors and the radial distances to the cluster centre. We derive the mean relative proper motion of NGC 6934 using stars with high membership probabilities from radial velocities (Smith and Bell 1986) or from their location in the colour‐magnitude diagram (Harris and Racine 1973). The relative proper motions of four Hipparcos stars in the field will be used to obtain the absolute proper motion of NGC 6934 once the extragalactically calibrated Hipparcos Output Catalogue is available.
The true rotational period of the Ap star HD 193722 = V 1584 Cyg
Authors: Hildebrandt G. , Scholz G. , Lehmann H. , Panov K. 
Published: July 2007

AbstractPhotometric observations of the Ap star HD 193722 give unambiguous proofs for a rotational period of P=8.5297 days in contradiction to the earlier found value of P=1.13316 days. Spectroscopic measurements yield a line width equivalent to the value v sin i=44.5 km/s. Both findings show convincingly that HD 193722 is an evolved Ap star with a position in the giant region of the HR diagram. This place falls into a domain occupied by the hypothetic Maia sequence.
The charged particle distribution due to emission in a magnetic field
Authors: Gunko Y. F. , Ponomaryv M. G. 
Published: July 2007

AbstractCharged particles emission in a magnetic field on the basis of Boltzman equation with source term is studied. The work develops the results of Narasimha (1962), where the neutral gas expansion into a vacuum is studied. The different specific cases of emission are given for moving sources. The results may be of use when we study phenomena which happen in plasma close to the Earth and in space, as well as for studies of phenomena which take place due to moving satellites in the ionosphere and in interplanetary or interstellar plasma.
Solar corona photometry by electropolarimetric and CCD observations during the eclipse of July 11, 1991
Authors: Kulidzanishvili V. I. , Georgobani D. G. 
Published: July 2007

AbstractThe observational data of the solar corona obtained during the solar eclipse of July 11, 1993, using both a electropolarimeter (EP) and a CCD matrix were processed. Using these data the photometry of the solar corona was carried out. The results of EP data were compared with those of the CCD data. It must be noticed here that the CCD data give us only the characteristics of the inner corona, while the EP data show the features of both the inner and the middle corona up to 4 solar radii.The standard flattening index ϵ was evaluated from both data. The dependence of ϵ on the distance from the solar limb was investigated. Three‐dimensional images of the coronal intensity distribution for different spectral lines are shown. Isophotes in Na and Ca lines with unusual features are plotted. Based on these data some ideas and conclusions on the type of the solar corona and the physical conditions in it are presented.
Construction of a diameter‐limited sample of galaxies in the northern sky. The catalogue
Authors: Bardelli S. , Zucca E. 
Published: July 2007

AbstractIn order to understand if the differences between the SSRS of Da Costa et al. (which is diameter‐limited) and the CfA survey (which is magnitude‐limited) are real or induced by the different selection criteria, the CfA survey has been directly compared with a diameter‐limited sample covering the same region of the sky (UDLS, Bardelli et al. 1991, Zucca et al. 1991).In this paper we present the data for the galaxies in the UDLS sample, in an updated version which collects velocity information from the literature until June 1993, leaving us with a velocity completeness better than ˜ 95%.
The difference between the nearby galaxies and the Virgo cluster
Authors: Schmidt K.‐H. , Boller Th. 
Published: July 2007

AbstractThe sample of galaxies within 7 Mpc has been compared with that of the Virgo cluster in order to find new and confirm already known differences which may be caused by the environment. The well‐known morphology‐density relation is found to be valid not only for luminous galaxies but also for faint objects. The differences in the global luminosity functions are mainly caused by the different composition of the samples, whereas the luminosity functions of narrow morphological subgroups, with the exception of the irregulars, probably are not dependent on the density or on other quantities. The already observed HI‐deficiency of the interstellar medium of the Virgo cluster spirals has been confirmed. There is a steep drop of this quantity with increasing distance from the dominant galaxies M 87 and M 49. The interstellar dust masses of Virgo cluster spirals and irregulars have been estimated from far‐infrared fluxes. These data have been combined with the HI masses in order to obtain the gas‐to‐dust ratios, which come out to be smaller by a factor of 4 for the Virgo cluster spiral galaxies than for the nearby systems, on the average. The gas‐to‐dust ratio is strongly correlated with the HI‐deficiency. These results support the concept of the ram pressure of the intracluster medium on the spiral galaxies in the core of the Virgo cluster.
The additional radiation of Cyg X‐1 at primary minimum
Authors: Voloshina I. , Lyuty V. M. 
Published: July 2007

AbstractNew UBV‐photoelectric observations of the well‐known massive X‐ray binary system Cyg X‐1/V 1357 Cyg are obtained near the primary minimum. The detailed analysis of these observations confirms the existence of additional blue radiation which appears as a narrow peak with an amplitude of 0.01–0.02 mag near phase 0.00 on the light curve (the superior conjunction of the relativistic component), firstly detected by Lyuty (1985). This emission does not appear at every orbital cycle. The appearance of this narrow peak of additional blue radiation on the light curve of Cyg X‐1 can be explained as the radiation of relativistic electrons in the disturbed magnetic field of the optical star in frames of the model proposed by Ikhsanov and Fabrika (1990).
The influence of the surroundings on the morphology of galaxies
Authors: Mahtessian A. P. , Movsessian V. H. , Khachikian E. Ye. , Tiersch H. 
Published: July 2007

AbstractThe characteristics of galaxies within galaxy groups are investigated as a function of the surroundings. It is shown that the relative number of the galaxies with different morphological type is correlated with the number of members within the group, but the fraction of E+S0 galaxies does not depend on the mean‐pairwise distance between the galaxies, the density of the luminous matter as well as the velocity dispersion in the group.
On the period changes of RR Lyrae variables in the globular cluster M3
Authors: Wenzel W. 
Published: July 2007

AbstractO – C diagrams of 78 RR Lyrae variables of the years 1963 to 1978 were used to investigate their comparability with the diagrams of 1895 to 1963. Only 5% have been proved to show a fundamentally deviating trend of the period change.
Radial velocities of the components of the Trapezium‐type multiple systems
Authors: Javakhishvili G. Sh. , Salukvadze G. N. 
Published: July 2007

AbstractFrom 1988 to 1989 radial velocities of 76 components of 46 Trapzium‐type multiple systems have been measured with the 125‐cm reflector of the Abastumani Astrophysical Observatory. In Table 1 a list of observations is given, containing the mean values of radial velocities, velocities of axial rotation, the halfwidth of contours and equivalent width.
Identification of D3 and Hα spicules
Authors: Khutsishvili E. V. 
Published: July 2007

AbstractBasing on the analysis of observational material obtained with the 53‐cm coronagraph in Abastumani, the author concludes that chromospheric spicules in hydrogen and helium lines are one and the same formation. Besides, it should be noted that, as a result of radial velocity measurements, it was found that hydrogen and helium D3 lines are emitted from different areas of the same spicule.
Stochastic forces in space plasmas with ion‐acoustic and lower‐hybrid‐drift turbulence
Authors: Meister C.‐V. 
Published: July 2007

AbstractA Langevin equation for charged particles in a plasma with electrostatic turbulence is developed from first principles and in consistency with the kinetic theory in polarization approximation. For the case of ion‐acoustic and electrostatic lower‐hybrid‐drift turbulence approximate expressions for the space‐time spectral density of the wave energy are given and estimates of the intensities of the stochastic wave forces are made. The application is done for the plasmas of the earth's magnetosphere, the solar wind and solar flares.It seems, that ion‐acoustic and electrostatic lower‐hybrid‐drift waves can contribute to electron chaotization in different regions of the space plasma.
Positional and photometric CCD observations of the comet Shoemaker‐Levy 9
Authors: Kiladze R. , Kvernadze T. , Ogadze G. , Inasaridze R. 
Published: July 2007

AbstractPositional and photometric CCD observations of the comet Shoemaker‐Levy 9 fragments were carried out at the Abastumani Astrophysical Observatory. Up to 15 named fragments were detected and their equatorial coordinates and magnitudes are reported. CCD frames were processed using DAOPHOT II. The internal precision of reference star positions down to 18m is 0.″7 and the mean error of photometry does not exceed ±0.3 mag.
Beobachtungen Kleiner Planeten. II
Authors: Börngen F. , Kirsch K. 
Published: July 2007

AbstractEs wird eine übersicht gegeben über die im Jahr 1981 auf Tautenburger Schmidtaufnahmen gefundenen Kleinen Planeten. Es wurden 294 Objekte entdeckt und für sie 614 Positionen gerechnet.
Approximate Solutions of the Equations of Motion of a Charged Particle in the Field of a Magnetic Dipole
Authors: Kustaanheimo P. E. , Tutein J. 
Published: July 2007

AbstractThree differential equations of the first order (26)—(28) which determine the trajectory are deduced. An approximate integration by means of elementary functions yields a set of formulas (in chapt. 13. Conclusions) that give a „window”︁ in the sky inside of which the radiation point of a high energy cosmic ray (monotonely bent in the magnetic field) must lie.
BIANCHI‐I‐Kosmen der BRANS‐DICKE‐Theorie für das Vakuum
Authors: Dyllong U. 
Published: July 2007

AbstractThe field equations of the BRANS‐DICKE theory are solved for a vacuum with the aid of a space‐time metric of BIANCHI‐I‐type. Two solutions are found. One of them corresponds to a generalization of the flat de SITTER‐universe. On the other side we have obtained the KASNER‐like solution on the basis of original the version of BRANS‐DICKE theory.
Singularity‐free static centrally symmetric solutions of some fourth order gravitational field equations
Authors: Fiedler B. , Schimming R. 
Published: July 2007

AbstractDie von TREDER vorgeschlagenen Gravitationsfeldgleichungen 4. Ordnung mit einer Linearkombination des Bachtensors und des Einsteintensors auf der linken Seite besitzen statische zentralsymmetrische Lösungen, welche in einer Umgebung des Symmetriezentrums analytisch und nicht flach sind.
Astronomische Längen‐und Breitendifferenzen der Basisobservatorien Irkutsk, Potsdam und Simeiz (Mitteilungen des Zentralinstituts für Physik der Erde, Nr. 1180)
Authors: Höpfner J. 
Published: July 2007

AbstractIn den Jahren 1980—1981 wurden auf den Stationen Irkutsk, Potsdam und Simeiz astronomische Beobachtungen an einem transportablen DANJON‐Astrolab zwecks Bestimmung von Längen‐ und Breitendifferenzen ausgeführt. — Es wird über die durchgeführten Beobachtungen und ihre Auswertung berichtet, wobei auch die benötigten Formeln zur astronomischen Längen‐ und Breitenbestimmung angegeben werden. Die erhaltenen Längen‐ und Breitenwerte werden eingeschätzt. Hiernach dient die gewogene Mittelung dazu, sie schrittweise zu verdichten. Dabei werden sie auf systematische Gruppendifferenzen und persönliche Fehler hin untersucht. Abschließend werden die Längen‐ und Breitendifferenzen unter Berücksichtigung der persönlichen Gleichungen der Beobachter abgeleitet. Ihre Genauigkeiten betragen zwischen ±0,0020 s und ±0,0028 s bzw. ±0,013”︁ und ±0,017”︁.
Transits of Mercury: Results of Belgrade Observations in 1970 and 1973
Authors: Protitch‐Benishek V. 
Published: July 2007

AbstractPhotographische Beobachtungen der Merkurdurchgänge vor der Sonne 1970 und 1973 an der Sternwarte Belgrad wurden zur Ermittlung der scheinbaren Halbmesser von Sonne und Merkur benutzt. Die mittleren Werte des Sonnenradius, reduziert auf die Längeneinheit, sind um ca. 1.3 größer als die Auwersschen Werte, wohingegen die Werte für den Merkur mit denen von LE VERRIER übereinstimmen.Für die Sonnenparallaxe wurden folgende Werte erhalten: 8.800 ± 0.008 (1970) und 8.788 ± 0.032 (1973) und als gewogenen Mittelwert: πs = 8.794 ± 0.013.
Values of the Atmospheric Density at 280 km Obtained from Spin Drag Data of COSMOS 54 Rocket
Authors: Mioc V. 
Published: July 2007

AbstractA set of atmospheric density values at a height of 280 km between MJD 39675—39702 is determined by using the spin drag data of COSMOS 54 rocket. For this purpose photometric observations from five tracking stations and data about the satellite and its orbital evolution were used. The density values determined firstly at the perigee height were reduced at a standard height of 280 km and then compared with density values determined by using orbital drag data of this rocket at the same height and in the same time interval. The agreement between the two sets of densities (determined by using two different methods) is satisfactory.
On‐line‐Steuerung eines lichtelektrischen Sternphotometers
Authors: Reimann H.‐G. , Pfau W. , Stecklum B. 
Published: July 2007

AbstractDie on‐line‐Steuerung eines photonenzählenden Photometers mit dem Kleinsteuerrechner KSR 4100 in der erweiterten Sprache INKA wird beschrieben. Charakteristische Größen des Photometers (Farbgleichungskoeffizienten, Totzeit) sind angegeben. Dabei erfolgte die Ermittlung der Totzeit mit einem neuen Verfahren unter Ausnutzung der Photonenstatistik bei Messungen mit hoher Zeitauflösung (1 ms).
Faint Blue Galaxies in the Virgo Cluster Region
Authors: BÖrngen F. 
Published: July 2007

AbstractFinding charts, coordinates, B magnitudes, and U – B color estimates are given for 110 faint blue galaxies located near the centre of the Virgo cluster of galaxies. The galaxies have been found by blinking on plates taken with the Tautenburg 52 inch SCHMIDT telescope.
The binary nature of the magnetic star β CrB
Authors: Oetken L. , Orwert R. 
Published: July 2007

AbstractThe radial velocity of the binary star β CrB was reinvestigated to look for the hypothetical third body, suggested by NEUBAUERS results. Under the assumption that a systematic difference of 1.4 km/sec between NEUBAUERS results from 1931–43 and ours from 1971–83 is of instrumental origin, the radial velocities of both epochs can be well represented with the same orbital elements: thus the probability for the existence of a third component in the system is reduced. The eccentricity and the angle of periastron passage of the visual orbit, derived from published speckle interferometric measurements, agree very well with the corresponding elements of the spectroscopic orbit. For the masses of the components those of giant resp. subgiant stars of type A8 and F5 are found. The geometry of the binary β CrB with a magnetic star as the primary component is demonstrated.
Observer dependence of past light cone initial data in cosmology
Authors: Dautcourt G. 
Published: July 2007

AbstractWe discuss some properties of the initial data introduced in previous articles to study the past light cone initial value problem in cosmology. A parametrization of the conformal cone metric (the geometrical part of the initial data) is proposed which is closely related to astronomical observations of image distrotions of distant extragalactic objects. The quantities used here as initial data have simple transformation properties under a Lorentz rotation of the oberver.
Photometric investigations of compact galaxies
Authors: Börngen F. , Kalloghlian A. T. 
Published: July 2007

AbstractNo exact definition of compact galaxes with regard to their degree of concentration exists up to now. 169 objects visually selected by ZWICKY respectively BÖRNGEN and KALLOGHLIAN in the field ZwCl 1710.4 + 6401 are analysed photometrically and morphologically. The brighness profiles are determined by means of equidensities calibrated into intensities. The different parts of these profiles are investigated with regard to their utility of an objective description of compact galaxies. Whereas the halo is not suitable, a classification is practicable by means of the gradient G of the middle part of the profile. Especially, it is shown that the (lg Imax, m)‐diagram is well suited to represent the compact galaxies. In an interval of some magnitudes in which the density of star images is not yet saturated the positions of stars and compact galaxies differ significantly. The star positions obey a linear relation which is used for the calibration of our method and for the derivation of the plate constants. By means of the characteristic quantity m0 and the compactness k one gets a quantitative characterization of compact galaxies and a subdivision into the classes K = 1, 2, and 3. Extreme compact galaxies (K = o) are difficult or not at all discernible from stars, galaxies of the class K = 4 are no more compact.
Some results of model calculations of the solar S‐component radio emission
Authors: Krüger A. , Hildebrandt J. 
Published: July 2007

AbstractNumerical calculations of special characteristics of the solar S‐component microwave radiation are presented on the basis of recent sunspot and plage models. Quantitative results are discussed and can be used for the plasma diagnostics of solar active regions by comparisons with observations with high spatial and spectral resolution
.The possibility of generalized applications to magnetic stars and stellar activity is briefly noted.
On tidal radius determination for a globular cluster
Authors: Ninkovica S. 
Published: July 2007

AbstractA tidal radius determination for a globular cluster based on its density minimum, which is caused by the galactic tidal forces and derivable from a model of the Galaxy, is proposed. Results obtained on the basis of the Schmidt model for two clusters are in a satisfactory agreement with those obtained earlier by means of other methods. A mass determination for the clusters through the tidal redius, when the latter one is identified with the cluster perigalactic distance, yields unusually large mass values. Probably, the tidal radius should be identified with the instantaneous galactocentric distance. Use of models more recent than the Schmidt one indicates that a globular cluster may contain a significant portion of an invisible interstellar matter.
New results on large‐scale structures
Authors: Kalinkov M. , Stavrev K. , Kuneva I. 
Published: July 2007

AbstractA new version of the magnetic‐tape catalog of ABELL clusters of galaxies is used to obtain redshift estimators and to generate two samples of clusters. A procedure for searching for superclusters of galaxies is applied and the results are given in tabular and graphic form. For a lmited homogeneous sample (distance 60–275 Mpc, galactic latitude B > 35°), 12 multiplets, having member clusters with known redshifts, are found. It is shown that the spatial covariance function for rich clusters has the form ξ = (r0/r)γ with r0 = 22.4 ± 1.8 Mpc and γ = 1.90 ± 0.25 for 3 Mpc ≲ r ≲ 80 Mpc.
Investigation of clusters of galaxies. I. Explanation of photometric scale of errors by light diffusion in a photographic emulsion
Authors: Baier F. W. , Ziener R. 
Published: July 2007

AbstractA photographic photometry in B and V was performed for 326 galaxies in the central field of the Coma cluster. We found an explanation (diffusion of light in the emulsion according to an earlier investigation of ZIENER) for the systematic deviation between the results from ROOD and BAUM and from GODWIN and PEACH in the V pass band. We conclude that the photometry of ROOD and BAUM is true. Diffusion also can explane the results of FONG, GODWIN, and METCALFE.
Boundary behaviour of accretion disks determined by gravity induced cooling near the black hole
Authors: Paul H. G. 
Published: July 2007

AbstractIn the framework of thin, rigorous relativistic accretion disks the inner boundary behaviour is studied taking into cosideration the internal energy of the disk plasma. Consuming the internal energy stored in the accretion flow the disk forms a cusplike wall in the effective gravitational potential; the disk matter is raised on higher levels of the angular momentum by cooling simultaneously. This gravity induced cooling leads to a rigorous braking of the radial accretion flow. There is a steep, inner boundary with a very small gap very close at the orbit of last bound motion of test matter. Especially natural boundary conditions can be imposed in contrast to the boundary value problem in the divergent, relativistic standard models.