scholarly journals On The Gegenschein and the Symmetry Plane

1991 ◽  
Vol 126 ◽  
pp. 147-150
Author(s):  
S. S. Hong ◽  
S. M. Kwon
Keyword(s):  
Symmetry Plane ◽  
Outer Part ◽  
Ecliptic Plane ◽  
Dust Concentration ◽  
Zodiacal Light ◽  
Zodiacal Cloud ◽  
Extended Region

AbstractUsing 3-dim density models of the zodiacal cloud, we have calculated brightness of the zodiacal light over an extended region around the anti-solar point. The isophotal contours of the model Gegenscheins differ from each other, morphologically, to the degree that they can differentiate the competing density models. The recently reduced Gegenschein observations of 2° resolution clearly favour the ellipsoid-type models to the fan-types, and also suggest that the surface of the densest dust concentration in the outer part of the cloud has its ascending node at longitude 100 ± 20° and is inclined 2 ± 0°.5 with respect to the ecliptic plane.

scholarly journals The Zodiacal Cloud Complex

1991 ◽  
Vol 126 ◽  
pp. 131-138
Author(s):  
A.C. Levasseur-Regourd ◽  
J.B. Renard ◽  
R. Dumont
Keyword(s):  
Optical Properties ◽  
Symmetry Plane ◽  
Ecliptic Plane ◽  
Interplanetary Dust ◽  
The Sun ◽  
Zodiacal Light ◽  
Zodiacal Cloud ◽  
Classical Models ◽  
Cloud Complex ◽  
Two Populations

AbstractThe physical properties of the interplanetary dust grains are, out of the ecliptic plane, mainly derived from observations of zodiacal light in the visual or infrared domains. The bulk optical properties (polarization, albedo) of the grains are demonstrated to depend upon their distance to the Sun (at least in a 0.1 AU to 1.7 AU range in the symmetry plane) and upon the inclination of their orbits (at least up to 22°). Classical models assuming the homogeneity of the zodiacal cloud are no longer acceptable. A hybrid model, with a mixture of two populations, is proposed. It suggests that various sources (periodic comets, asteroids, non periodic comets...) play an important role in the replenishment of the zodiacal cloud complex.

scholarly journals Optical Properties of Interplanetary Dust in the Tangential Plane

1991 ◽  
Vol 126 ◽  
pp. 199-202
Author(s):  
J.B. Renard ◽  
A.C. Levasseur-Regourd ◽  
R. Dumont
Keyword(s):  
Optical Properties ◽  
Symmetry Plane ◽  
Ecliptic Plane ◽  
Interplanetary Dust ◽  
Polarization Degree ◽  
Zodiacal Light ◽  
Tangential Plane ◽  
Zodiacal Cloud ◽  
Local Polarization ◽  
Local Intensity

AbstractLocal intensity and emissivity, and consequently local polarization degree, temperature and albedo, can be retrieved from optical and thermal observations of zodiacal light. The local polarization degree (normalized at constant solar distance and phase angle) is found to decrease with elevation above the symmetry plane of the zodiacal cloud. The heterogeneity of the cloud, established towards the symmetry pole, is here demonstrated in the tangential plane (almost perpendicular to the ecliptic plane at 1 AU). We present a map of the local polarization degree in this plane.

scholarly journals The Symmetry Plane of the Zodiacal Cloud Near 1 AU

1980 ◽  
Vol 90 ◽  
pp. 49-53
Author(s):  
Nebil Y. Misconi
Keyword(s):  
Solar System ◽  
Heliocentric Distance ◽  
Symmetry Plane ◽  
Orbital Plane ◽  
Zodiacal Light ◽  
Zodiacal Cloud ◽  
Invariable Plane

Analysis of zodiacal light observations from Mt. Haleakala, Hawaii show that the symmetry plane of the zodiacal cloud near 1 A.U. is close to the invariable plane of the solar system. Since the symmetry plane of the inner zodiacal cloud is close to the orbital plane of Venus (Misconi and Weinberg, 1978; Leinert et al., 1979), we suggest that the symmetry plane changes inclination with heliocentric distance.

scholarly journals 1.3.3 Consequences of the Inclination of the Zodiacal Cloud on the Ecliptic

1976 ◽  
Vol 31 ◽  
pp. 121-121
Author(s):  
R. Robley
Keyword(s):  
Solar System ◽  
Exponential Distribution ◽  
Inclination Angle ◽  
Radial Direction ◽  
Heliocentric Distance ◽  
Ecliptic Plane ◽  
Interplanetary Dust ◽  
Zodiacal Light ◽  
Invariant Plane ◽  
Zodiacal Cloud

Assuming that the decrease in the density of the interplanetary dust follows an exponential distribution both in the transverse and radial direction, we can write n = no Exp(-(h/H)-(r-l/R)), where h is the distance from the ecliptic plane and r the heliocentric distance both expressed in astronomical units (a.u.); then we show that the modulation of the radiance B(90, 0) of the zodiacal light observed at the ecliptic pole defines the parameter H as a function of the inclination angle B between the zodiacal cloud and the ecliptic plane; moreover, the experimental value of the ratio B(90, 0)/B(90, 90) defines the parameter R. It can be deduced that the flatness of the zodiacal cloud, expressed by R/H, is < 5 and that the plane of symmetry of the zodiacal cloud is very close to that of the invariant plane of the solar system (B<2°).

scholarly journals Dynamical zodiacal cloud models constrained by high resolution spectroscopy of the zodiacal light

Icarus ◽  
2008 ◽  
Vol 194 (2) ◽  
pp. 769-788 ◽  
Author(s):  
Sergei I. Ipatov ◽  
Alexander S. Kutyrev ◽  
Greg J. Madsen ◽  
John C. Mather ◽  
S. Harvey Moseley ◽  
...  
Keyword(s):  
High Resolution ◽  
High Resolution Spectroscopy ◽  
Zodiacal Light ◽  
Zodiacal Cloud ◽  
Cloud Models

scholarly journals Electromagnetic Escape of Dust from the Solar System

1996 ◽  
Vol 150 ◽  
pp. 31-34 ◽  
Author(s):  
Douglas P. Hamilton ◽  
Eberhard Grün ◽  
Michael Baguhl
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Solar System ◽  
Solar Magnetic Field ◽  
Ecliptic Plane ◽  
Dust Particles ◽  
Orbital Dynamics ◽  
Zodiacal Cloud ◽  
Current Configuration ◽  
Zodiacal Dust

AbstractCollisions of asteroids and among Zodiacal cloud particles produce large amounts of submicron-sized debris, much of which is immediately ejected from our solar system by electromagnetic forces. We investigate the trajectories of tiny grains started on circular uninclined orbits within the Zodiacal cloud and find that they reach high ecliptic latitudes during the current configuration of the solar magnetic.field, perhaps accounting for particles detected by the Ulysses spacecraft at latitudes up to 80°. When the solar magnetic field is reversed, particles are more strongly confined to the ecliptic plane and escape the solar system less readily. Both fluxes and spatial densities of sub-micron sized Zodiacal dust particles vary with time through the dependence of orbital dynamics on the 22-year solar cycle.

scholarly journals 1.1.2 Helios Zodiacal Light Experiment

1976 ◽  
Vol 31 ◽  
pp. 19-23 ◽  
Author(s):  
E. Pitz ◽  
C. Leinert ◽  
H. Link ◽  
N. Salm
Keyword(s):  
Angular Resolution ◽  
Ecliptic Plane ◽  
The Other ◽  
Integration Time ◽  
The Sun ◽  
Effective Wavelength ◽  
The South ◽  
Zodiacal Light

The Z.L. experiment consists of 3 photometers which are mounted rigidly into the s/c with orientations of about 15°, 30° and 90° south of the s/c – XY-plane, which coincides in orbit with the ecliptic plane (see Fig.1). Helios is spinning uith 1 Hz, and the integration time of the experiment is 513 revolutions. The 90° – photometer always looks to the south ecliptic pole and one revolution of the s/c is divided into 8 sectors to get information on the polarization of Z.L. The polarization is measured by a fixed polaroid foil within the photometer which is rotated by the s/c. In the other two photometers one revolution is split into 32 sectors with different angular resolution. Near the antisun where the gradient in Z.L. intensity is small, the sector length is 4 times the length near the sun (see Fig.2). In these 2 photometers the polarization is obtained by 3 differently oriented polarization foils moved by stepping motors. Intensity and polarization of Z.L. is measured in 3 different colors, which are near the international UBV – system (Ažusienis and Straižs 1969), the effective wavelength shifted by about 100 Å to the blue end.

scholarly journals Dynamics of Micrometeoroids

1980 ◽  
Vol 90 ◽  
pp. 293-298 ◽  
Author(s):  
E. Grün ◽  
H. A. Zook
Keyword(s):  
Heliocentric Distance ◽  
Ecliptic Plane ◽  
Interplanetary Dust ◽  
Spatial Density ◽  
Orbital Elements ◽  
Zodiacal Light ◽  
Consistent Picture ◽  
Time Variations ◽  
Pioneer 10

Recent observations of zodiacal light have established a reliable and consistent picture of the spatial distribution of interplanetary dust in the ecliptic plane. The spatial density nr varies with heliocentric distance r according to a power law nr ∝ r−ν. From Helios observations an exponent v = 1.3 is derived for the distance interval from 0.08 A.U. to 1 A.U. (Link et al. 1976). Outside the earth's orbit the Pioneer 10 and 11 results suggest a higher exponent v = 1.5 for the distance interval from 1 A.U. to 3.3. A.U. (Hanner et al., 1976). Giese and Grün (1976) showed that the results from zodiacal light observations are compatible with the micrometeoroid fluxes derived from in situ measurements and lunar crater statistics. They found that micrometeoroids in the size range from 10 μm to 100 μm radii (corresponding roughly to 10−8g to 10−5g) contribute most to the zodiacal light brightness.The orbital distribution of large interplanetary particles (10−6 g < m < 10−3g) is known from meteor observations. Sekanina and Southworth (1975) reported average orbital elements of these particles: ā ∼ 1.25 A.U., ē ∼ 0.4 and ī ∼ 20°. Orbital information on micrometeoroids (m < 10−8g) is obtained from in situ detectors on board the Pioneer 8 and 9 and Helios 1 spaceprobes and the HEOS-2 satellite. Characteristics of the different micrometeoroid experiments are given in Table 1. There is almost no time overlap in the data taking intervals of the experiments. Therefore one has to assume that there are no time variations of the meteoroid flux on the time scale of 1 to 10 years if one compares the results from the different experiments. This assumption may be violated for the smallest of the observed particles (m < 10−13g) due to strong electromagnetic interaction of these particles with the interplanetary magnetic field (Morfill and Grün 1979).

scholarly journals Disentangling the main populations of the Zodiacal Cloud from Zodiacal Light observations

1998 ◽  
Vol 50 (6-7) ◽  
pp. 473-476 ◽  
Author(s):  
R. Dumont ◽  
J. B. Renard ◽  
A. C. Levasseur-Regourd ◽  
J. L. Weinberg
Keyword(s):  
Zodiacal Light ◽  
Zodiacal Cloud

scholarly journals The Motion of Interplanetary Dust Particles

1985 ◽  
Vol 85 ◽  
pp. 81-84
Author(s):  
I.R. East ◽  
N.K. Reay
Keyword(s):  
Radial Velocity ◽  
Ecliptic Plane ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
Light Spectrum ◽  
Zodiacal Light ◽  
Interplanetary Dust Particles ◽  
Radial Velocity Curve ◽  
Fabry Perot ◽  
Hyperbolic Trajectories

AbstractRadial velocity measurements on the solar MgI 5183.618Å Fraunhofer absorption line in the Zodiacal Light spectrum have been made with a microprocessor-controlled servo-stabilised Fabry-Perot interferometer. Observations were made at 5 and 10 degree intervals in the ecliptic plane between morning and evening elongations of 25 degrees. These new data are of much greater precision and coverage than any previously obtained. Obtained over a two year period, the observations show a consistent evening/morning asymmetry in the radial velocity curve with the Gegenschein receding from the Earth at 4 Km/sec. These data do not support the hypothesis that the majority of interplanetary dust grains are in hyperbolic trajectories.

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