VERTICAL RELAXATION OF A MOONLET PROPELLER IN SATURN'S A RING

Journal Article · Fri Mar 01 00:00:00 EST 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/765/1/L4· OSTI ID:22130878

Hoffmann, H.; Seiss, M.; Spahn, F. ^[1]

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1. Institute of Physics and Astronomy, University of Potsdam, D-14476 Golm (Germany)

Two images, taken by the Cassini spacecraft near Saturn's equinox in 2009 August, show the Earhart propeller casting a 350 km long shadow, offering the opportunity to watch how the ring height, excited by the propeller moonlet, relaxes to an equilibrium state. From the shape of the shadow cast and a model of the azimuthal propeller height relaxation, we determine the exponential cooling constant of this process to be {lambda} = 0.07 {+-} 0.02 km{sup -1}, and thereby determine the collision frequency of the ring particles in the vertically excited region of the propeller to be {omega}{sub c}/{Omega} = 0.9 {+-} 0.2.

• OSTI ID: 22130878
• Journal Information: Astrophysical Journal Letters, Vol. 765, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COLLISIONS
COOLING
EQUILIBRIUM
IMAGES
RELAXATION
RINGS
SATELLITES
SATURN PLANET