scholarly journals An Astrometric Catalog of Four Million Stars

1990 ◽  
Vol 141 ◽  
pp. 482-482 ◽  
Author(s):  
V. V. Nesterov ◽  
V. S. Kisliuk ◽  
H. I. Potter
Keyword(s):  
Comparative Studies ◽  
List Type ◽  
Full Information ◽  
Type Number ◽  
Proper Motions ◽  
Methods Of Determination ◽  
General Reduction

The goal of the present study is (1)Completion of a general reduction of the Carte du Ciel astrophotographic catalogs, measurement of the positions in them on modern astronegatives, derivation of proper motions and compilation of a catalog of stars to magnitude 12.5.(2)Copying the data of all 272 volumes of astrophotographic catalogues onto magnetic tapes (all together 8.5 million measurements).(3)Measurement of modern astronegatives on FON-OBZOR-S and FOKAT-Y programs.(4)Studies of the magnitude equation of the AGK3 catalog and other catalogs which will be presumably used as reference catalogs.(5)Development and comparative studies of several methods of determination of equatorial coordinates on the basis of full information on astronegative measurements. Application of these methods to compilation of the catalog of 4 million stars.

An alert in the psycho-social-health intervention. A graphic testimony of a real case with autism spectrum disorder

2011 ◽  
Vol 26 (S2) ◽  
pp. 758-758
Author(s):  
J.A. García ◽  
A.S. Raya ◽  
E.S. del Arco
Keyword(s):  
Autism Spectrum ◽  
Real Case ◽  
List Type ◽  
Type Number ◽  
High Functioning ◽  
The Family ◽  
Pertinent Information ◽  
New Challenges ◽  
Professional Intervention

The graphic papers of Pablo, 14 years, diagnosed of autism of high functioning, serve as a sign of alert when facing what underlies after the specializing professional intervention.A few letters, a few drawings, and a few words that show the powerlessness, the suffering and the absence of contextual specific adequacy.In this work we study, from the analysis of a real case, some excellent aspects in the psychosociosanitary attention, such as:-The need for compilation of pertinent information-The need for elimination of prejudices-The need for respect to the family-The need for specialized formation-The need for search of a shared communicative code-The need for search of strategies of social interaction-The need for empathy-The need for search of contextual specific adequacy-The need for rigorous rules in the physical containment.-The need of a turned over of adapted information-The need to respect the psychoevolutive situation of the patient-The need to give priority to the person on the illness.A testimony that should serve as a warning for those institutions, administrations and professionals who are thinking of having put all the resources to its scope.A testimony that should serve to contribute information and new challenges to those other professionals who do not stop their determination of conceptual and/or clinical anxious research.

scholarly journals Photographic Observation of Stellar Occultations

1988 ◽  
Vol 98 ◽  
pp. 144-145
Author(s):  
A. Tomić ◽  
N. Čabrić ◽  
V. Čelebonović
Keyword(s):  
List Type ◽  
Type Number ◽  
The Moon ◽  
Photographic Observation ◽  
High Quality ◽  
Crucial Step ◽  
Stellar Occultations ◽  
On Line

Stellar occultations are usually observed visually, but this can also be done photographically. Our method has some advantages: –the obtained moments of contacts refer to the smoothed lunar limb,–the error in the determination of contacts is calculable,–the error may be less than in visual work,–the reduction of photographs is fast, due to the application of an “on-line” computer [1].In order to achieve all this, it is necessary to make a series of photographs of the Moon and the object being occulted before the first and after the last contact. This is a crucial step in our method, because the photographs must be of high quality. This demands two things: –the images of the occulted object and the Moon must be reliably recorded and–the illuminated limb of the Moon must give optimal darkening on the film.

scholarly journals C. Proper Motions and Radial Velocities

1955 ◽  
Vol 1 ◽  
pp. 33-42
Keyword(s):  
Stellar System ◽  
Radial Velocities ◽  
Detailed Account ◽  
List Type ◽  
Type Number ◽  
Proper Motions ◽  
Extensive Data ◽  
System A ◽  
The Galaxy

One of the most important fields for co-ordination in galactic research is the organization of programmes for proper motions and radial velocities. The need for accurate and more extensive data on stellar motions is strongly felt in connexion with the studies of the structure of the Galaxy and of the relation between the physical and the kinematical characteristics of the stars. Not long ago it seemed that meridian astronomy and photographic astrometry were rather remote from the main problems in astrophysics. It is realized now, that the study of stellar motions gives highly important information on the evolution of the stars and of the stellar system. A detailed account of the needs in this field, as discussed at the conference, follows: (1)propermotions: photographicastrometryoffaintstars

The Separation of Principal Stresses in Photo-Elastic Analysis

1946 ◽  
Vol 50 (432) ◽  
pp. 974-985 ◽  
Author(s):  
E. K. Frankl
Keyword(s):  
Stress Pattern ◽  
Design Tool ◽  
Complete Analysis ◽  
List Type ◽  
Elastic Analysis ◽  
Type Number ◽  
Principal Stresses ◽  
Suitable Material ◽  
Polarised Light

The photo-elastic method can be used for either of two main purposes:a)As a qualitative design tool to obtain indications of possibly unsuspected sources of stress concentration.(b)As a means of obtaining a complete analysis of a two-dimensional stress problem, i.e., the determination of the separate magnitudes of the principal stresses at any point, as well as the direction of the principal planes relative to some axis of reference.All that is required for (a) is the stress pattern which becomes visible and can be photographed when a loaded model cut from a sheet of suitable material is placed in a field of circularly polarised light.

scholarly journals A Program For A New Reduction Of Plates Of The Astrographic Catalogue

1988 ◽  
Vol 133 ◽  
pp. 441-444
Author(s):  
S. Röser ◽  
H. Jahreiß
Keyword(s):  
List Type ◽  
Proper Motions ◽  
The Past ◽  
Frequent Use ◽  
Readable Form ◽  
Ideal Tool ◽  
Machine Readable ◽  
Machine Readable Form ◽  
The Ideal

The Astrographic Catalogue is the major source of accurate first epoch coordinates of stars down to about 11 mag all over the sky. Therefore it could be the ideal tool for the determination of proper motions in this range of magnitudes - see also for example Fresneau (1985). There were mainly three reasons which prevented in the past a frequent use of this catalogue: 1)Apart from the „french“ zones (Lacroute 1981) the AC is not available in machine readable form.2)Only measured plate coordinates x,y and plate constants mostly derived with the AGK1 as reference catalogue have been published.3)The lack of easy to use software for a new reduction.

Twenty Years of Progress in X-Ray Diffraction Techniques

1961 ◽  
Vol 5 ◽  
pp. 1-12
Author(s):  
Andre Guinier
Keyword(s):  
Electron Microscopy ◽  
List Type ◽  
X Rays ◽  
Type Number ◽  
Rational Utilization ◽  
X Ray Diffraction ◽  
New Approach ◽  
X Ray ◽  
Near Future

AbstractAlthough no revolutionary advance has been achieved in the last two decades, X-ray diffraction is not to be considered as a quiescent field of physics. Actually many improvements, in theory as well as in experiment, slight by themselves but very numerous, have considerably increased the efficiency of techniques such as the determination of crystal structures, the analysis of crystalline phases, and the applications of X-rays to various problems of the physics of solids. Only the two last points will be dealt with here:1.Crystalline phase analysis. The development of a satisfactory atlas of powder patterns has been too slow, and the data are not yet complete and precise enough to permit a rational utilization of the modern diffractometers. A very interesting new approach is the systematic indexing of the powder patterns which would be possible with computers. In the near future, anyone should be able to analyze a powder at any temperature as an easy routine experiment.2.The study of lattice defects. X-ray techniques are now in competition with electron microscopy, the development of which has been very successful in recent years. Now we have a better understanding of the possibilities of both techniques. X-rays give better results to determine the statistics of an extended disorder even if it is slight (e.g., degrees of order in a solid solution), and the microscope is more powerful for the detection of large but rare defects (e.g., dislocations).

scholarly journals Fundamental Parameters and the Helium Content of Eclipsing Spectroscopic Binaries

1978 ◽  
Vol 80 ◽  
pp. 433-436
Author(s):  
H.E. Jørgensen
Keyword(s):  
Stellar Evolution ◽  
Stellar Atmosphere ◽  
Spectroscopic Binaries ◽  
List Type ◽  
Type Number ◽  
Helium Content ◽  
Fundamental Parameters ◽  
Effective Temperatures ◽  
Hr Diagram

Today we know accurate masses, radii, surface gravities and luminosities or effective temperatures of a very small number of stars. There are several reasons for deriving accurate parameters of stars. I shall mention only four problems:(i)checking stellar evolution calculations, particularly calculations of isochrones, using binaries,(ii)derivation of helium content in stars of different age,(iii)checking log g derived from photometry and stellar atmosphere calculations,(iv)determination of accurate positions in the HR diagram to get an independent check on calibrations of photometric systems.

Reference Coordinate System Requirements for Geodesy and Ocean Dynamics

1975 ◽  
Vol 26 ◽  
pp. 93-114
Author(s):  
R. S. Mather
Keyword(s):  
Sea Level ◽  
Motion Vector ◽  
Ocean Dynamics ◽  
Sea Surface ◽  
List Type ◽  
Type Number ◽  
Mean Sea Level ◽  
Crustal Motion ◽  
Four Dimensions

AbstractThe requirements for systems of reference in geodesy and ocean dynamics should be framed against the background of the distinct possibility of achieving in the foreseeable future measurements with a resolution of 1 part in 108. The current techniques promising this precision, with one exception, are based on observations to extraterrestrial sources/responders. The principal geodetic goals calling for such precision are, broadly stated, the determination of:1. Positions of stations in global tracking networks.2. Crustal motion.3. Polar motion.4. The radial component of instantaneous sea surface position from satellite altimetry for the estimation of phenomena related to ocean circulation.5. Earth model improvement.These goals cannot be achieved without the definition of adequate models for relating measurements from observing stations on Earth to extraterrestrial objects, possibly in an iterative manner in the first instance.While the specific choice of a system of geodetic reference is not critical for determinations of position in three dimensions, the maintenance of the continuity of geodetic concepts at the highest level of resolution in terms of four-dimensional considerations narrows the possible alternatives available.Criteria desirable in such a system of reference for observations of the highest precision made from the surface of a non-rigid Earth undergoing secular crustal motion are the following:1. These observations should be capable of direct relation to the system of reference in four dimensions.2. The crustal motion vector at a point should be defined in terms of the variations of the coordinatesof that pointwith time.3. Near-Earth orbital positions should have unambiguous relationships to the origin of ocean geoid determinations in four dimensions.4. Coordinates on the adopted system of reference should have relevance over an epoch of practical significance (e.g., one year).5. The scale for the space as obtained from the observations should not be influenced by factors other than the velocity of light and the adopted definition for the second.An important corollary is that only one point should be treated as “fixed” at the surface of the nonrigid Earth. Positional variations which have a periodic character, effective over an epoch of observation or less, are best treated as effects to be removed from observations by appropriate modeling. Reported secular changes in mean sea level require that the geoid be defined in relation to mean sea level in four dimensions for any determination of sea surface topography, thereby completing a unified system of reference which, would meet all the requirements of high-precision geodesy and ocean dynamics.

scholarly journals La Jolla Natural Radiocarbon Measurements III

Radiocarbon ◽  
1963 ◽  
Vol 5 ◽  
pp. 254-272 ◽  
Author(s):  
Carl L. Hubbs ◽  
George S. Bien ◽  
Hans E. Suess
Keyword(s):  
Age Determination ◽  
University Of California ◽  
List Type ◽  
Type Number ◽  
Background Count ◽  
Optimal Material ◽  
La Jolla ◽  
University Of Bern ◽  
The University

During 1962 the La Jolla Radiocarbon Laboratory continued to follow essentially the same technique as in previous years. Three counters were used: 1.The “Bern Counter,” an Oeschger-Houtermans instrument manufactured at the Physical Institute of the University of Bern; described in La Jolla I (p. 197).2.The “Brussels Counter,” another Oeschger-Houtermans instrument, manufactured in Brussels by Manufacture Belge de Campes et de Matériel Électronique, S. A.; characterized in La Jolla II (p. 204).3.The “400-cc La Jolla Counter,” recently constructed at the University of California, San Diego to facilitate the age determination of samples containing less than 1 g of carbon. Because the first model, now in use, was constructed of brass—not the optimal material—the background count is relatively high (ca. 5.0 counts/min). Advantages lie in its high stability. For samples that yield 0.5 L or more of acetylene, this counter can be used quite satisfactorily. Check runs, using the same sample in this counter and in the Bern and Brussels counters, agree closely.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Sign in / Sign up

Export Citation Format

Share Document