Diffraction effects in the processing of television observations of stellar occultations by the moon

2011 ◽  
Vol 27 (1) ◽  
pp. 50-57
Author(s):  
V. V. Kleshchonok
Keyword(s):  
The Moon ◽  
Stellar Occultations ◽  
Diffraction Effects

Discovery and Measurement of Double Stars by Lunar Occultations

1965 ◽  
Vol 5 ◽  
pp. 28-37
Author(s):  
R. Edward Nather ◽  
David S. Evans
Keyword(s):  
The Moon ◽  
Double Stars ◽  
Stellar Diameters ◽  
Diffraction Effects

When a star is occulted by the dark limb of the Moon its apparent intensity drops to zero very quickly. MacMahon (1909) proposed that the time of disappearance would measure the diameter of the star, but Eddington (1909) demonstrated that diffraction effects at the lunar limb would lengthen the apparent time of disappearance to about 20 msec, and suggested that these effects would greatly limit the usefulness of the technique. MacMahon’s paper indicates that he was aware that stellar duplicity could be detected from occultation observations, but he did not amplify the point and Eddington did not comment on it. While it has been demonstrated theoretically by Williams (1939) and experimentally by Whitford (1939) and others that stellar diameters of a few arcmsec can be measured by this technique, its use for the discovery and measurement of double stars has been only incidental to other programs (O’Keefe and Anderson, 1952; Evanset al., 1954). Properly exploited, the method can contribute materially to the study of double stars.

Stellar occultations by small bodies - Diffraction effects

1987 ◽  
Vol 93 ◽  
pp. 1549 ◽  
Author(s):  
F. Roques ◽  
M. Moncuquet ◽  
B. Sicardy
Keyword(s):  
Small Bodies ◽  
Stellar Occultations ◽  
Diffraction Effects

scholarly journals The Investigation of Lunar Limb Structure by Means of Stellar Occultations

1971 ◽  
Vol 2 ◽  
pp. 601-606 ◽  
Author(s):  
David S. Evans
Keyword(s):  
Standard Model ◽  
Point Source ◽  
Relative Motion ◽  
Position Angle ◽  
Small Scale ◽  
The Moon ◽  
The Standard Model ◽  
Stellar Occultations ◽  
Limb Structure

It has long been recognized that the analysis of occultation traces from point source stars might provide a means of investigating the structure of the lunar limb on a remarkably small scale, certainly of tens of meters, possibly on a scale of meters.The routine process of analysis of such an occultation trace produces a curve fitted to the standard model for a point source, in which the observed rate of fringe passage is matched to that computed from the rate and position angle of the relative motion of the moon with respect to the star background and the position angle of the point at which the occultation occurs. If θυ is the position angle towards which the relative motion of the lunar center takes place, θ that at which the occultation occurs, and ψ = θν — θ, then the predicted rate of the lunar limb perpendicular to itself at this point isRp = V cos ψwhere V is the velocity of the lunar center.

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 Discovery and Measurement of Double Stars by Lunar Occultations

1971 ◽  
Vol 5 ◽  
pp. 28-37
Author(s):  
R. Edward Nather ◽  
David S. Evans
Keyword(s):  
The Moon ◽  
Double Stars ◽  
Diffraction Effects

When a star is occulted by the dark limb of the Moon its apparent intensity drops to zero very quickly. MacMahon (1909) proposed that the time of disappearance would measure the diameter of the star, but Eddington (1909) demonstrated that diffraction effects at the lunar limb would lengthen the apparent time of disappearance to about 20 msec, and suggested that these effects would greatly limit the usefulness of the technique.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Laboratory Simulation of Lunar Luminescence

1962 ◽  
Vol 14 ◽  
pp. 441-444 ◽  
Author(s):  
J. E. Geake ◽  
H. Lipson ◽  
M. D. Lumb
Keyword(s):  
Science And Technology ◽  
Laboratory Simulation ◽  
The Moon ◽  
Physics Department ◽  
Luminescent Spectrum

Work has recently begun in the Physics Department of the Manchester College of Science and Technology on an attempt to simulate lunar luminescence in the laboratory. This programme is running parallel with that of our colleagues in the Manchester University Astronomy Department, who are making observations of the luminescent spectrum of the Moon itself. Our instruments are as yet only partly completed, but we will describe briefly what they are to consist of, in the hope that we may benefit from the comments of others in the same field, and arrange to co-ordinate our work with theirs.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

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