Sporadic meteors and the zodiacal cloud

2015 ◽  
pp. 531-544
Author(s):  
Peter Jenniskens
Keyword(s):  
Zodiacal Cloud ◽  
Sporadic Meteors

scholarly journals DYNAMICAL MODEL FOR THE ZODIACAL CLOUD AND SPORADIC METEORS

2011 ◽  
Vol 743 (2) ◽  
pp. 129 ◽  
Author(s):  
David Nesvorný ◽  
Diego Janches ◽  
David Vokrouhlický ◽  
Petr Pokorný ◽  
William F. Bottke ◽  
...  
Keyword(s):  
Dynamical Model ◽  
Zodiacal Cloud ◽  
Sporadic Meteors

Asteroid collisions as origin of debris disks: Asteroid shape reconstruction from BNAO Rozhen photometry

2019 ◽  
Vol 15 (S350) ◽  
pp. 451-453
Author(s):  
G. Apostolovska ◽  
E. Vchkova Bebekovska ◽  
A. Kostov ◽  
Z. Donchev
Keyword(s):  
Laboratory Experiments ◽  
Extrasolar Planets ◽  
Shape Reconstruction ◽  
Inversion Method ◽  
Debris Disks ◽  
Shape Parameters ◽  
Zodiacal Cloud ◽  
Photometric Observations ◽  
Different Shapes ◽  
Asteroid Surface

AbstractAs a result of collisions during their lifetimes, asteroids have a large variety of different shapes. It is believed that high velocity collisions or rotational spin-up of asteroids continuously replenish the Sun’s zodiacal cloud and debris disks around extrasolar planets (Jewitt (2010)). Knowledge of the spin and shape parameters of the asteroids is very important for understanding collision asteroid processes. Lately photometric observations of asteroids showed that variations in brightness are not accompanied by variations in colour index which indicate that the shape of the lightcurve is caused by varying illuminations of the asteroid surface rather than albedo variations over the surface. This conclusion became possible when photometric investigations were combined with laboratory experiments (Dunlap (1971)). In this article using the convex lightcurve inversion method we obtained the sense of rotation, pole solutions and preliminary shape of 901 Brunsia.

scholarly journals The Velocity Distribution of Sporadic Meteors. II

1952 ◽  
Vol 112 (1) ◽  
pp. 21-39 ◽  
Author(s):  
M. Almond ◽  
J. G. Davies ◽  
A. C. B. Lovell
Keyword(s):  
Velocity Distribution ◽  
Sporadic Meteors

scholarly journals Collisional Evolution of the Inner Zodiacal Cloud

2021 ◽  
Vol 2 (5) ◽  
pp. 185 ◽  
Author(s):  
J. R. Szalay ◽  
P. Pokorný ◽  
D. M. Malaspina ◽  
A. Pusack ◽  
S. D. Bale ◽  
...  
Keyword(s):  
Zodiacal Cloud ◽  
Collisional Evolution

scholarly journals Meteor Studies

1988 ◽  
Vol 98 ◽  
pp. 170-172 ◽  
Author(s):  
B.A. Lindblad
Keyword(s):  
New Zealand ◽  
Great Britain ◽  
20Th Century ◽  
19Th Century ◽  
Main Interest ◽  
Naked Eye ◽  
A Minor ◽  
The 19Th Century ◽  
Sporadic Meteors ◽  
Important Milestone

Historically meteor astronomy is one area where amateurs have always been able to make significant contributions. In fact, in the 19th century, it was amateur naked eye and telescopic observations which laid down much of the foundations of meteor astronomy. References to this work can be found in any textbook on meteors. The 19th century observers concentrated on counting meteors, estimating magnitudes and plotting the meteor paths on star maps. Their main interest was to determine hourly rates and shower radiants. An important milestone was Denning’s radiant catalogue (Denning 1882), which included 4367 shower radiants. Although it is now believed that many of these radiants are spurious, the catalogue is still a useful reference. Unfortunately Denning and other 19th century observers often combined sporadic meteors observed on different nights into a minor stream radiant. This habit of “radiant hunting” is even today quite popular among some amateur observers. However, in all fairness it should be emphasized that most of the 20th century amateur meteor observers applied very strict criteria to their radiant determinations. Names such as J.M. Prentice in Great Britain, R.A. McIntosh in New Zealand and R. Rigollet in France may be mentioned.

scholarly journals 11. Some unusual spectra of meteors from the Palomar 18-inch Schmidt file

1968 ◽  
Vol 33 ◽  
pp. 119-127
Author(s):  
R. Barbon ◽  
J. A. Russell
Keyword(s):  
Atmospheric Condition ◽  
Nitrogen Molecule ◽  
The Other ◽  
Positive Group ◽  
Principal Feature ◽  
Atmospheric Stratification ◽  
Sporadic Meteors ◽  
Different Altitudes

Five meteoric spectra have been studied that were obtained during the period mid-June to mid-December, 1966. They include spectra of a Perseid, a Geminid, and three sporadic meteors. Four were photographed on Royal Pan emulsion without a filter; the Geminid on Tri X Aerecon with a GG11 filter.Lines in the spectrum of one of the sporadic meteors indicate that two meteoroidal fragments were involved which diverged with increasing atmospheric penetration and which flared at different altitudes, indicating that the flares were not the result of atmospheric stratification.The second sporadic and the Perseid were photographed about 2½ hours apart. The sodium D line is strong in the Perseid but does not appear in the sporadic spectrum. If present, it is blended with the diagonal sequence Δv = + 4 of the first positive group of the neutral nitrogen molecule, which appears in both spectra. A line questionably identified as the forbidden line of oxygen at 5577 Å appears faintly in the sporadic. The strength of the N2 sequence in these two spectra, and the absence of the D line in the sporadic, are very unusual. The proximity in time of appearance of these two spectra, and the absence of the N2 bands from the other two sporadic spectra, suggest that a temporary atmospheric condition may be responsible for the strength of the nitrogen radiation.The Geminid has as its principal feature the Δv = + 3 sequence of the first positive group of N2. We have not previously observed this band in meteors as low in velocity as the Geminids.

scholarly journals The Influence of the Atmosphere on Radar Meteor Rates

1980 ◽  
Vol 90 ◽  
pp. 101-104
Author(s):  
W.G. Elford.
Keyword(s):  
Initial Diameter ◽  
Meteor Trail ◽  
Radio Studies ◽  
The Difference ◽  
Sporadic Meteors ◽  
Radar Meteor ◽  
Sharp Cutoff ◽  
Selection Of

The majority of radio studies of meteors have been carried out at frequencies higher than 17MHz and most of the rate observation at frequencies above 30MHz. At these frequencies a severe height selection of meteors occurs. In Figure 1(a) are shown the normalized height distributions of sporadic meteors observed at Adelaide on frequencies of 27MHz and 2MHz (Brown, 1976). The sharp cutoff of the latter distribution below 87 km is instrumental. The difference in the height distributions is due to the effect of the finite diameter of a meteor trail on its radar detectability. If the trail diameter is ≪ λ signals from the near and far edges reinforce but as the trail expands due to diffusion and the diameter becomes ≃ λ/4, interference reduces the amplitude. A meteor trail, produced by a particle with a velocity of 30 km s−1, has an initial diameter of 0.4m at 80 km, 2.0m at 104 km and 4.0m at 116 km.

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