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Title: FORMATION OF A PROPELLER STRUCTURE BY A MOONLET IN A DENSE PLANETARY RING

Journal Article · · Astrophysical Journal Letters
;  [1]
  1. Center for Computational Astrophysics, National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan)

The Cassini spacecraft discovered a propeller-shaped structure in Saturn's A. This propeller structure is thought to be formed by gravitational scattering of ring particles by an unseen embedded moonlet. Self-gravity wakes are prevalent in dense rings due to gravitational instability. Strong gravitational wakes affect the propeller structure. Here, we derive the condition for the formation of a propeller structure by a moonlet embedded in a dense ring with gravitational wakes. We find that a propeller structure is formed when the wavelength of the gravitational wakes is smaller than the Hill radius of the moonlet. We confirm this formation condition by performing numerical simulations. This condition is consistent with observations of propeller structures in Saturn's A.

OSTI ID:
21562697
Journal Information:
Astrophysical Journal Letters, Vol. 732, Issue 2; Other Information: DOI: 10.1088/2041-8205/732/2/L23; ISSN 2041-8205
Country of Publication:
United States
Language:
English