scholarly journals Desiderata for Fk5

1968 ◽  
Vol 1 ◽  
pp. 301-305 ◽  
Author(s):  
W. Fricke ◽  
W. Gliese
Keyword(s):  
Celestial Mechanics ◽  
Reference System ◽  
Inertial Frame ◽  
Large Range ◽  
Fundamental System ◽  
Systematic Errors ◽  
Frame Of Reference ◽  
Proper Motions ◽  
Astronomical Research ◽  
Positional Astronomy

A fundamental catalogue compiled from independent and differential observations of stellar positions at various epochs provides the fundamental system of positions and proper motions of the stars. The system ought to be compiled in such a way that it represents the inertial frame of reference as accurately as practicable. Its direct purpose is to serve as the reference system of positional astronomy. It should fulfil the requirements of astronomical research, in particular in celestial mechanics and galactic research, as well as the demands of the astronomical determinations of time and of latitudes. It has also to fulfil the requirements of geodesy and navigation. For all these purposes the system must be uniform over the whole sky (free from regional systematic errors), and it has to be uniform over a large range of stellar magnitudes (free from errors depending on the magnitude of the stars).

scholarly journals Proper Motions of OB Stars in Both Hemispheres

1974 ◽  
Vol 61 ◽  
pp. 227-227
Author(s):  
Haruo Yasuda
Keyword(s):  
Southern Hemisphere ◽  
Fundamental System ◽  
Systematic Errors ◽  
Radial Velocities ◽  
Distance Scale ◽  
Proper Motions ◽  
Stellar Kinematics ◽  
Ob Stars

From a comparison between the rotational velocities derived from radial velocities and space motions of OB stars, large systematic errors of FK4 proper motions in the southern hemisphere are evaluated; these may be expected, from the known accuracy of the FK4. The error of adopted distance scale is also examined. It is suggested that meridian observations of OB stars should be extended to the southern hemisphere to further researches, not only on stellar kinematics, but also on the fundamental system.

scholarly journals Ephemerides and Celestial Mechanics

1986 ◽  
Vol 7 ◽  
pp. 65-68
Author(s):  
Victor K. Abalakin
Keyword(s):  
Celestial Mechanics ◽  
Inertial Frame ◽  
Frame Of Reference ◽  
The Real ◽  
The Universe ◽  
Natural Way

When solving some abstract problems in mechanics related to the dynamics of bodies and systems, the notion of an inertial frame of reference is introduced in an apparently clear and natural way by simply drawing its coordinate axes and then paying no further attention to the system of reference which is then taken for granted. If we turn, however, towards investigations of the real stellar and planetary world, or as Sir James Jeans put it, “… to the Universe around us,” we immediately face the question of how to practically construct a useful and obvious model of the inertial frame of reference sufficiently close to reality.

scholarly journals Fundamental Catalogues

1988 ◽  
Vol 133 ◽  
pp. 95-102
Author(s):  
W. Gliese
Keyword(s):  
Polar Motion ◽  
Fundamental System ◽  
Systematic Errors ◽  
Proper Motions ◽  
Experienced Observer ◽  
Single Night

The first plates for the great enterprise, the Carte du Ciel or the Astrographic Catalogue, were taken in 1891. At that time no fundamental system existed which was usable as a basis for reference stars over the whole sky and was commonly accepted by the astronomical community. Therefore reference stars were taken from available catalogues, sometimes updated to the epoch of the plates by application of proper motions. Other observatories used their own reference stars specially observed on transit circles. For the last-mentioned method the work at the Cape Observatory is an instructive example which was described by Sir David Gill, an experienced observer, in a catalogue of Astrographic Standard Stars (Gill, 1906). The methods of observation are fully described in the volumes of the Cape Meridian Observations. For the derivation of proper motions southern catalogues dating from 1835 to 1900 were used, applying Newcomb's values for precession. The determination and elimination of serious systematic errors played an important role. “Eye-and-Ear” observers had their personal errors which even changed with the years for the same person, occasionally even during tiresome long watches in a single night. Further sources of errors include: None-reversible instruments, zenith discontinuities, magnitude equations, possible changes of flexure, pivot errors and their variations, and unsufficient knowledge of the polar motion in old catalogues. Many of these questions were investigated and described in extended introductions to observational catalogues but in some cases such problems were only incompletely explained. Reference stars for the Astrographic Catalogues were observed on various “fundamental system” if fundamental at all.

scholarly journals The Contribution Of The Danjon Astrolabe To The Improvement Of The Fundamental Reference System at The Southern Hemisphere

1988 ◽  
Vol 133 ◽  
pp. 359-367
Author(s):  
F. Noël
Keyword(s):  
Southern Hemisphere ◽  
Reference System ◽  
Fundamental System ◽  
Systematic Errors ◽  
Historic Review ◽  
Fundamental Reference

An historic review is made of the observation programs with Danjon astrolabes which were carried out or are in progress at the southern hemisphere. The consistency of their results in the research of systematic errors of the FK4 Fundamental System, largely confirmed by other observation techniques, is shown. The Cape and Santiago astrolabe catalogues, the largest ones derived so far for southern stars, are briefly reviewed.

scholarly journals CPC2 Reduction with Hipparcos and Proper Motions in The Southern Hemisphere

1998 ◽  
Vol 11 (1) ◽  
pp. 551-551
Author(s):  
N. Zacharias ◽  
M.I. Zacharias ◽  
C. de Vegt ◽  
C.A. Murray
Keyword(s):  
Southern Hemisphere ◽  
Systematic Errors ◽  
Reference Star ◽  
Proper Motions ◽  
Positional Accuracy ◽  
Star Catalog ◽  
Naval Observatory ◽  
Celestial Reference System ◽  
First Time ◽  
Better Than

The Second Cape Photographic Catalog (CPC2) contains 276,131 stars covering the entire Southern Hemisphere in a 4-fold overlap pattern. Its mean epoch is 1968, which makes it a key catalog for proper motions. A new reduction of the 5687 plates using on average 40 Hipparcos stars per plate has resulted in a vastly improved catalog with a positional accuracy of about 40 mas (median value) per coordinate, which comes very close to the measuring precision. In particular, for the first time systematic errors depending on magnitude and color can be solved unambiguously and have been removed from the catalog. In combination with the Tycho Catalogue (mean epoch 1991.25) and the upcoming U.S. Naval Observatory CCD Astrograph Catalog (UCAC) project proper motions better than 2 mas/yr can be obtained. This will lead to a vastly improved reference star catalog in the Southern Hemisphere for the final Astrographic Catalogue (AC) reductions, which will then provide propermotions for millions of stars when combined with new epoch data. These data then will allow an uncompromised reduction of the southern Schmidt surveys on the International Celestial Reference System (ICRS).

scholarly journals Hipparcos Astrometric Results

1998 ◽  
Vol 11 (1) ◽  
pp. 536-538
Author(s):  
J. Kovalevsky
Keyword(s):  
Proper Motion ◽  
Reference System ◽  
Systematic Errors ◽  
One Dimensional

Abstract The astrometric results of Hipparcos include the positions at epoch (1991.25), the proper motion in the new IAU extragalactic reference system (ICRS), and parallaxes for about 118 000 stars. One dimensional positions are also given for 48 asteroids and 3 satellites. Due to the non-isotropy of the scanning law, the uncertainties are position dependent. Some indications of the remaining correlations are given. Various tests and comparisons show that systematic errors in parallax, if any, are not larger than 0.1 millisecond of arc.

Positional Astronomy, Celestial Mechanics

1983 ◽  
pp. 154-176
Author(s):  
S. Böhme ◽  
Walter Fricke ◽  
H. Hefele ◽  
I. Heinrich ◽  
W. Hofmann ◽  
...  
Keyword(s):  
Celestial Mechanics ◽  
Positional Astronomy

scholarly journals Dilation of Time and Newton’s Absolute Time

2019 ◽  
pp. 1-20
Author(s):  
Stefan Von Weber ◽  
Alexander Von Eye
Keyword(s):  
Light Propagation ◽  
Inertial Frame ◽  
Background Radiation ◽  
Frame Of Reference ◽  
Relativity Theory ◽  
Absolute Space ◽  
Light Sources ◽  
Membrane Theory ◽  
Absolute Time ◽  
Microwave Background Radiation

The Cosmic Membrane theory states that the space in which the cosmic microwave background radiation has no dipole is identical with Newton’s absolute space. Light propagates in this space only. In contrast, in a moving inertial frame of reference light propagation is in-homogeneous, i.e. it depends on the direction. Therefore, the derivation of the dilation of time in the sense of Einstein’s special relativity theory, i.e., together with the derivation of the length contraction under the constraint of constant cross dimensions, loses its plausibility, and one has to search for new physical foundations of the relativistic contraction and dilation of time. The Cosmic Membrane theory states also that light paths remain always constant independent on the orientation and the speed of the moving inertial frame of reference. Effects arise by the dilation of time. We predict a long term effect of the Kennedy-Thorndike experiment, but we show also that this effect is undetectable with today’s means. The reason is that the line width of the light sources hides the effect. The use of lasers, cavities and Fabry-Pérot etalons do not change this. We propose a light clock of special construction that could indicate Newton’s absolute time t0 nearly precisely.

Positional Astronomy, Celestial Mechanics

1992 ◽  
pp. 218-244
Author(s):  
G. Burkhardt ◽  
U. Esser ◽  
H. Hefele ◽  
Inge Heinrich ◽  
W. Hofmann ◽  
...  
Keyword(s):  
Celestial Mechanics ◽  
Positional Astronomy
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