scholarly journals L’Astronomie des Etoiles Doubles face a la Mission Astrometrique du Satellite Hipparcos

1983 ◽  
Vol 62 ◽  
pp. 260-260 ◽  
Author(s):  
J. Dommanget
Keyword(s):  
Optical Design ◽  
Double Star ◽  
Scanning Process ◽  
Wide Pairs

SummaryThe Hipparcos satellite is described as well as the scanning process of the sky by its optical design, as a consequence of the satellite’s motion. From these data, the possibilities of the mission is deduced and applied in the case of the binaries.Discussion is made of what may be expected for different double star categories including spectroscopic, astrometric, close visual and wide pairs. Information are given on how proposals should be made for lists of binaries that should be observed.

scholarly journals The Importance of Wide-System Studies for Stellar Evolution and Galactic Dynamics

1984 ◽  
Vol 80 ◽  
pp. 23-28
Author(s):  
J. Dommanget
Keyword(s):  
Double Star ◽  
Galactic Dynamics ◽  
Time Interval ◽  
Short Time Interval ◽  
Main Task ◽  
Multiple Star ◽  
Multiple Systems ◽  
Wide Pairs ◽  
Wide System ◽  
Short Time

AbstractWide pairs and wide multiple systems have been too much neglected during many years by visual double star astronomers with the argument that only close visual pairs (short periods) may lead to mass-determinations in a relatively short time interval. But mass-determination should not be considered as the only interest of double star astronomy, even if it is of a fundamental nature.Today, it appears that researches on the origin and the evolution of the wide systems are urgently wanted, not only for the understanding of the evolution of the stellar medium, but also for a better knowledge of galactic dynamics. Some examples are given.Presently, the main task for double star specialists will be an important improvement in double and multiple star census for all kind of systems: close, medium, and wide. The Hipparcos satellite will probably add some important informations in that respect but ground-based observations also remain of the highest importance (radial velocities, photometry, astrometry, etc.).

scholarly journals CCD Astrometry and Photometry of Visual Double Stars: Northern Hipparcos Wide Pairs Measured in the Years 2003-2005

2006 ◽  
Vol 2 (S240) ◽  
pp. 613-618
Author(s):  
D. Sinachopoulos ◽  
P. Gavras ◽  
Th. Medupe ◽  
Ch. Ducourant ◽  
O. Dionatos
Keyword(s):  
Angular Separation ◽  
Double Star ◽  
Solar Neighborhood ◽  
Common Origin ◽  
Double Stars ◽  
The North ◽  
Visual Double Stars ◽  
Wide Pairs ◽  
Stellar Formation ◽  
Formation And Evolution

AbstractThe relative positions of Hipparcos visual double star components are currently known with a precision around fifty mas. Modern CCD astrometric observations of these objects achieve an accuracy of their angular separation between ten and twenty mas per observation. New CCD measurements have been obtained at Kryonerion Observatory in the north hemisphere. They provide current relative positions of visual double stars which are at least twice as accurate as the ones provided by Hipparcos. The new measurements will permit us to extract the physical pairs from the sample, and the double stars, which have components of common origin. Final statistics of these systems will improve our understanding of stellar formation and evolution rates of wide binaries in the solar neighborhood.

Use of the Magnetostatic Analogue In Electromagnetic Lens Engineering

1970 ◽  
Vol 28 ◽  
pp. 360-361
Author(s):  
John W. Coleman
Keyword(s):  
Boundary Conditions ◽  
High Performance ◽  
Force Fields ◽  
Optical Design ◽  
Direct Conversion ◽  
Design Engineering ◽  
Design Data ◽  
Scalar Potentials ◽  
Geometric Elements ◽  
At Will

In the design engineering of high performance electromagnetic lenses, the direct conversion of electron optical design data into drawings for reliable hardware is oftentimes difficult, especially in terms of how to mount parts to each other, how to tolerance dimensions, and how to specify finishes. An answer to this is in the use of magnetostatic analytics, corresponding to boundary conditions for the optical design. With such models, the magnetostatic force on a test pole along the axis may be examined, and in this way one may obtain priority listings for holding dimensions, relieving stresses, etc..The development of magnetostatic models most easily proceeds from the derivation of scalar potentials of separate geometric elements. These potentials can then be conbined at will because of the superposition characteristic of conservative force fields.

Optical design to boost the performance of perovskite based tandem solar cells

2018 ◽  
Author(s):  
Miguel Anaya ◽  
Gabriel Lozano ◽  
Mauricio Calvo ◽  
Hernán Míguez
Keyword(s):  
Solar Cells ◽  
Optical Design ◽  
Tandem Solar Cells
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