scholarly journals The New Catalogue of Positions and Proper Motions of 5115 Bright Stars Compiled as the Result of the International “Bright Stars” Program

1995 ◽  
Vol 166 ◽  
pp. 353-353
Author(s):  
O.A. Molotaj ◽  
V.V. Tel'Nyuk-Adamchuk ◽  
N.A. Chernega ◽  
N.D. Kanivec'
Keyword(s):  
Proper Motion ◽  
The Other ◽  
Standard Errors ◽  
Star System ◽  
Proper Motions ◽  
International Program ◽  
Motion System ◽  
Stellar Astronomy ◽  
The Mean ◽  
The One

At Kyiv University Observatory, in accordance with IAU resolution, the Combined Catalogue of Positions and Proper Motions of 5115 Bright Stars in the FK5 system for Epoch and Equinox J2000.0 (BSC, see reference) has been compiled using 20 source catalogues obtained within the framework of ‘Bright Stars’ International Program. The source catalogs are Bordeaux-66, Bucharest-65, Bucharest-68, Belgrade-79, Cape-68, Kharkiv-70n, Kharkiv-70s, Kyiv-66, Kyiv-73, El Leoncito-70, Moscow-76, Mykolaiv-65, Perth-70, Perth-75, Santiago-65, Santiago-67, Strasbourg-65, Tashkent-64, Tokyo-68, Washington-66. The BSC accumulates around 30,000 source catalogue positions observed within 1960-1980. The standard errors of BSC do not exceed 0.1 arcsec and 0.25 arcsec/cy for positions and proper motions, respectively. The systematic differences between BSC and FK5 in positions for the mean BSC epoch 1970 as a rule do not exceed several hundredths of arcsec. A comparison of the BSC with the PPM catalogue indicates that in the latter the accuracy of positions and proper motions of the ordinary bright stars is slightly worse than that of average values given by the authors of the PPM. It is important to note that the comparison of the BSC with PPM for various star subsets shows deviations of both the HPS bright star system and the rest of the PPM bright stars, on the one hand, from the stars of the FK5 Extension contained in the PPM on the other hand. To examine the BSC proper motion system the stellar astronomy constants and correction to precession have been determined using the BSC proper motions. The parameters obtained agree with the standard ones. But the Oort constants are slightly smaller than those of standard.The BSC catalogue as a whole is acceptable for astrometry usage with respect to both accidental and systematic accuracy.

scholarly journals Statistical HR Diagrams for One Hundred and Fifteen Thousand Proper-Motion Stars

1978 ◽  
Vol 80 ◽  
pp. 63-64
Author(s):  
Willem J. Luyten
Keyword(s):  
Proper Motion ◽  
Tangential Velocity ◽  
Complete Data ◽  
The Other ◽  
Proper Motions ◽  
Real Situation ◽  
The Real ◽  
Using Data ◽  
The One ◽  
Hr Diagram

Since regular HR diagrams require apparent magnitudes, colors or spectra, and parallaxes, and such complete data are available for relatively few stars, there may be some advantage in making up diagrams which utilize proper motions instead of parallaxes, and are thus statistically similar to an HR diagram. The reduced proper motion, first used by Hertzsprung, is defined as H = m + 5 + 5log μ, but may also be written as H = M + 5log T, where T is the tangential velocity, and is expressed in astronomical units per year. A diagram plotting H against color will thus contain the considerable dispersion in tangential velocity which is a serious disadvantage. However, this is outweighed by two practical advantages. First the one and the same person who does the proper motion survey can, and does also determine the other two quantities needed. Second, when using data obtained from such a proper motion survey one deals, statistically, with all the stars within a given distance and the results, therefore, are much more representative of the real situation in space than many HR diagrams which often contain an unrealistic preponderance of giants.

The Effect of Waking Suggestion on Post-Hypnotic Amnesia

1981 ◽  
Vol 11 (1) ◽  
pp. 44-46 ◽  
Author(s):  
D.P. Fourie
Keyword(s):  
Point Of View ◽  
The Other ◽  
Hypnotic Susceptibility ◽  
The Subject ◽  
The Mean ◽  
The Difference ◽  
The One ◽  
The Relationship ◽  
Female Subjects

It is increasingly realized that hypnosis may be seen from an interpersonal point of view, meaning that it forms part of the relationship between the hypnotist and the subject. From this premise it follows that what goes on in the relationship prior to hypnosis probably has an influence on the hypnosis. Certain of these prior occurences can then be seen as waking suggestionns (however implicitly given) that the subject should behave in a certain way with regard to the subsequent hypnosis. A study was conducted to test the hypothesis that waking suggestions regarding post-hypnotic amnesia are effective. Eighteen female subjects were randomly divided into two groups. The groups listened to a tape-recorded talk on hypnosis in which for the one group amnesia for the subsequent hypnotic experience and for the other group no such amnesia was suggested. Thereafter the Stanford Hypnotic Susceptibility Scale was administered to all subjects. Only the interrogation part of the amnesia item of the scale was administered. The subjects to whom post-hypnotic amnesia was suggested tended to score lower on the amnesia item than the other subjects, as was expected, but the difference between the mean amnesia scores of the two groups was not significant.

scholarly journals Use of the Overlap Method for the Connexion of Proper Motions to Galaxies Problems of the Zone Without Nebulae

1970 ◽  
Vol 7 ◽  
pp. 188-196
Author(s):  
P. Lacroute
Keyword(s):  
The Other ◽  
Proper Motions ◽  
The One ◽  
Overlap Method

There are two methods for connecting the proper motions to the galaxies. The one used under the direction of A. N. Deutsch at Pulkovo, and the other method at the Lick Observatory.Only the method used by the Lick Observatory allows the use of overlapping plates. It is the only one which will be dealt with in this first part.

On the capture of interstellar matter by stars

1940 ◽  
Vol 36 (3) ◽  
pp. 314-322 ◽  
Author(s):  
R. d'E. Atkinson
Keyword(s):  
Radial Velocity ◽  
The Other ◽  
Interstellar Matter ◽  
Centre Of Gravity ◽  
Compelling Reason ◽  
Other Hand ◽  
The Mean ◽  
The One ◽  
The Individual ◽  
Capture Radius

The derivation given by Hoyle and Lyttleton for an accretion formula proposed by them is examined. A number of arguments against its validity are put forward, especially that on the one hand their capture radius depends on the theorem that if the velocity of certain masses of gas after collision is less than the velocity of escape at the point, they will not in fact escape, while on the other hand it is clear (and is now admitted) that the gas cannot in fact move with this velocity at all. It is also shown that since, ex hypothesi, the individual molecules will all, on the average, retain their hyperbolic velocities, there is not the compelling reason for their capture that there appeared to be in Hoyle and Lyttleton's argument, where only the mean radial velocity of the centre of gravity of the mass was considered. Further, it seems improbable that the temperature of the interstellar matter can be low enough for the initial assumptions of their theory to hold.

Struktur von Schmelzen aus dem System Wismut-Antimon mittels Neutronenbeugung

1976 ◽  
Vol 31 (1) ◽  
pp. 90-101 ◽  
Author(s):  
Peter Lamparter ◽  
Siegfried Steeb ◽  
Walter Knoll
Keyword(s):  
Neutron Diffraction ◽  
Coordination Number ◽  
Covalent Binding ◽  
The Other ◽  
Nearest Neighbour ◽  
Neighbour Distance ◽  
The Mean ◽  
The One ◽  
Subsidiary Maxima ◽  
Versus Concentration

Neutron diffraction work (λ = 0.695 Å) was done with molten Bi-Sb-alloys in the temperature range between 550 and 750 °C. Furthermore molten Bi was investigated at 300 °C. The interference functions show subsidiary maxima especially for alloys with higher Sb-concentrations. Evaluation yields, that the melts contain two different kinds of structure:a) The one kind shows coordination number 9 and a statistical distribution of the atoms of two components. This kind is more inetal-like.b) The other kind shows coordination number 3, consists of non-centered tetrahedra with smaller nearest neighbour distance. It shows covalent binding.In molten Sb the nearest neighbour distance amounts up to 3.16 - 3.19 Å for theo ne kind and up to 2.64 -2.78 Å fort he other kind, which yields an mean distance of 2.99 Å, which was observed. The dependence of the concentration of the statistical kind of meld, of the (Sb)4-, and the (Bi)4-kind from the concentration of the whole melt is given.By the model described the run of the measured mean coordination number and the mean distance versus concentration can be well explained.

Asymptotic independence of counts in isotropic planar point processes of phase-type

2000 ◽  
Vol 32 (2) ◽  
pp. 363-375
Author(s):  
Marie-Ange Remiche
Keyword(s):  
Poisson Process ◽  
Arbitrary Shape ◽  
Point Processes ◽  
The Other ◽  
Asymptotic Independence ◽  
Planar Point ◽  
Phase Type ◽  
Disjoint Sets ◽  
The Mean ◽  
The One

The isotropic planar point processes of phase-type are natural generalizations of the Poisson process on the plane. On the one hand, those processes are isotropic and stationary for the mean count, as in the case of the Poisson process. On the other hand, they exhibit dependence of counts in disjoint sets. In a recent paper, we have proved that the number of points in a square window has a Poisson distribution asymptotically as the window is located far away from the origin of the process. We extend our work to the case of a window of arbitrary shape.

scholarly journals VI. The specific heats of metals and the relation of specific heat to atomic weight.—Part III

1904 ◽  
Vol 203 (359-371) ◽  
pp. 139-149 ◽  
Keyword(s):  
Specific Heat ◽  
Atomic Weight ◽  
The Other ◽  
Influence Of Temperature ◽  
Specific Heats ◽  
Weight Part ◽  
Chemical Combination ◽  
Influence Of Temperature On ◽  
The Mean ◽  
The One

The law of Neumann assumes that when an atom enters into chemical combination it retains the same capacity for heat as when in the uncombined or elemental state. This generalisation is, however, based on the values observed for the mean specific heats of elements and their compounds between 0° and 100° C. Attention was directed in Part II. of this investigation to the great differences found in the influence of temperature on the specific heats of various metals, such as aluminium on the one hand, and silver or platinum on the other. The experiments now about to be described were undertaken with the object of ascertaining to what extent these differences persist in the compounds of such elements.

scholarly journals Tables of the variation, through a cycle of nine years, of the mean height of the barometer, mean temperature, and depth of rain, as connected with the prevailing winds, influenced in their direction by the occurrence of the lunar apsides, with some concluding observations on the result

1843 ◽  
Vol 4 ◽  
pp. 226-227
Keyword(s):  
The Other ◽  
Mean Temperature ◽  
The Mean ◽  
The One

From the Tables here given, the author draws the following conclusions:— 1 The barometer is higher under the lunar apogee, than under the perigee; the mean height in the former case being 29·84517, and in the latter, 29·75542. 2. The mean temperature is lower under the apogee than under the perigee; that of the former being 48°·7126, and of the latter, 49°·0356. The mean of the whole year was 48°·7126. 3. The rain of the weeks following the apsis exceeds that under the perigee; but with two striking exceptions in the annual result of nine years, the one in the wettest, and the other in the driest year of the cycle.

scholarly journals Globular clusters in the era of precision astrometry

2019 ◽  
Vol 14 (S351) ◽  
pp. 412-415
Author(s):  
Paolo Bianchini
Keyword(s):  
Formation Mechanism ◽  
Proper Motion ◽  
Measurement Errors ◽  
Globular Clusters ◽  
Tangential Component ◽  
Proper Motions ◽  
The Mean ◽  
Motion Measurements ◽  
Precision Astrometry

Abstracthe study of the kinematics of globular clusters (GCs) offers the possibility of unveiling their long term evolution and uncovering their yet unknown formation mechanism. Gaia DR2 has strongly revitalized this field and enabled the exploration of the 6D phase-space properties of Milky Way GCs, thanks to precision astrometry. However, to fully leverage on the power of precision astrometry, a thorough investigations of the data is required. In this contribution, we show that the study of the mean radial proper motion profiles of GCs offers an ideal benchmark to assess the presence of systematics in crowded fields. Our work demonstrates that systematics in Gaia DR2 for the closest 14 GCs are below the random measurement errors, reaching a precision of ∼0.015 mas yr−1 for mean proper motion measurements. Finally, through the analysis of the tangential component of proper motions, we report the detection of internal rotation in a sample of ∼50 GCs, and outline the implications of the presence of angular momentum for the formation mechanism of proto-GC. This result gives the first taste of the unparalleled power of Gaia DR2 for GCs science, in preparation for the subsequent data releases.

scholarly journals Numerical effects of gravitational light deflection on the determination of the equinox and equator

1986 ◽  
Vol 114 ◽  
pp. 205-211
Author(s):  
J. A. Hughes ◽  
D. K. Scott ◽  
C. A. Smith
Keyword(s):  
Coordinate System ◽  
Proper Motion ◽  
Minor Planets ◽  
The Sun ◽  
Light Deflection ◽  
Proper Motions ◽  
Motion System ◽  
Celestial Equator ◽  
The Right

Observations of the sun and major and minor planets made by transit circle telescopes are used to determine positions of the equinox and the celestial equator and, by repeated observing programs, the motions of these fiducial references. Long series of such absolute observations, when combined into catalogs such as the FK5, yield a fundamental coordinate system which is an observational approximation to an ideal, dynamically defined coordinate system. In such a system the equinox, for example, is defined implicitly by the right ascensions (at mean epoch) and the proper motions of the stars included in the catalog system, together with the adopted constant of precession. It may be noted that independent, highly accurate determinations of the latter quantity thus help to improve the fundamental proper motion system.

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