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| Titel |
Moon-influenced ringlets and edges in Saturn's rings |
| VerfasserIn |
Nicole Albers, Miodrag Sremcevic, Larry Esposito |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250057664
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| Zusammenfassung |
| Cassini observations during Saturn equinox have revealed a perplexing
amount of structure at the B ring edge. It is still a matter of
ongoing debate just how much of the observed structure is intrinsic to
the rings and how much is attributable to the influences of
ring-moons. We have analyzed ring edges and ringlets in order to
disentangle the question of the structure's origin using primarily
Cassini UVIS data. Among others objects of study include the Maxwell
ringlet in the C ring (which does not have a ring-moon associated
resonance), the Titan ringlet (Titan 1:0 ILR), the Huygens ringlet
(weakly associated with the Mimas 2:1 ILR), and the outer B ring edge
(Mimas 2:1 ILR).
The Maxwell ringlet exhibits a clear m=1 pattern consistent with a
freely precessing ringlet; the Titan and Huygens ringlet have pattern
speeds slightly faster than the free precession expected at their
location. While the Maxwell ringlet has a clearly linear
radius-width-relation consistent with uniform precession, neither the
Huygens nor Titan ringlet do. The later also show much stronger
deviations from a single m-mode shape of their edges, suggestion
non-trivial contributions from the ring-moons.
Saturn's outer B ring edge is the most prominent of the
moon-influenced ring edges. Voyager 2 imaging provides a previously
unpublished, nearly 270deg azimuthal coverage and high-resolution
images that show a dominant m=2 pattern as well as local disturbances
similar to those reported in Cassini imaging (Spitale and Porco,
2010). The shape of the edge is clearly dominated by the influence of
the moon Mimas while its orientation seems to librate following Mimas'
orbital changes. |
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