相关论文: The propeller and the frog

"Propellers" are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno 2010); the longitude residuals of the best-observed propeller, "Bl\'eriot," appear consistent with a…

The reconstruction of the orbital evolution of the propeller structure Bl\'eriot orbiting in Saturn's A ring from recurrent observations in Cassini ISS images yielded a considerable offset motion from the expected Keplerian orbit (Tiscareno…

The observation of the non-Keplerian behavior of propeller structures in Saturn's outer A ring (Tiscareno et al. 2010, Seiler et al. 2017, Spahn et al. 2018) raises the question, how the propeller responds to the wandering of the central…

We report the discovery of several large "propeller" moons in the outer part of Saturn's A ring, objects large enough to be followed over the 5-year duration of the Cassini mission. These are the first objects ever discovered that can be…

Kilometer-sized moonlets in Saturn's A ring create S-shaped wakes called "propellers" in surrounding material. The Cassini spacecraft has tracked the motions of propellers for several years and finds that they deviate from Keplerian orbits…

Hundred meter sized objects have been identified by the Cassini spacecraft in Saturn's A ring through the so-called "propeller" features they create in the ring. These moonlets should migrate, due to their gravitational interaction with the…

We analyze several thousand Cassini ISS images in order to study the inner edge of the Keeler gap in Saturn's outer A ring. We find strong evidence for an m=32 perturbation with a mean amplitude of radial variation of 4.5 km. Phase analysis…

We study the vertical extent of propeller structures in Saturn's rings. Our focus lies on the gap region of the propeller and on non-inclined propeller moonlets. In order to describe the vertical structure of propellers we extend the model…

The Cassini spacecraft discovered a propeller-shaped structure in Saturn's A ring. This propeller structure is thought to be formed by gravitational scattering of ring particles by an unseen embedded moonlet. Self-gravity wakes are…

Planets close to their stars are thought to form farther out and migrate inward due to angular momentum exchange with gaseous protoplanetary disks. This process can produce systems of planets in co-orbital (Trojan or 1:1) resonance, in…

Among the great discoveries of the Cassini mission are the propeller-shaped structures created by small moonlets embedded in Saturn's dense rings. We analyze images of the sunlit side of Saturn's outer A ring, which show the propeller…

We revisit the dynamics of Prometheus and Pandora, two small moons flanking Saturn's F ring. Departures of their orbits from freely precessing ellipses result from mutual interactions via their 121:118 mean motion resonance. Motions are…

The motions of small moons through Saturn's rings provide excellent tests of radial migration models. In theory, torque exchange between these moons and ring particles leads to radial drift. We predict that moons with Hill radii r_H ~ 2-24…

We present an extensive data set of ~150 localized features from Cassini images of Saturn's Ring A, a third of which are demonstrated to be persistent by their appearance in multiple images, and half of which are resolved well enough to…

We propose a mechanism for the observed non-keplerian motion (Tiscareno et al. 2010, ApJL) of "propeller" moons embedded in Saturn's rings. Our mechanism, in which radial variations in surface density -- external to, and unaffected by, the…

In some planetary systems, the orbital periods of two of its members present a commensurability, usually known by mean-motion resonance. These resonances greatly enhance the mutual gravitational influence of the planets. As a consequence,…

We show that the combination of a weak magnetic propeller and accretion disc resonances can effectively halt accretion in short period cataclysmic variables for large fractions of their lifetimes. This may help to explain the discrepancy…

For radio pulsars in orbit with a compact companion, pulsar timing observations have proved to be a powerful tool for identifying the physical nature of the companion. Unfortunately, perhaps the most intriguing system where such a tool…

We study the periodic enhancement of either trailing or leading segments of the resonance elliptical rings in the dynamical model of the Galaxy which reproduces distributions of observed velocities derived from Gaia DR3 (EDR3) data along…

The majority of extrasolar planets discovered to date have significantly eccentric orbits, some if not all of which may have been produced through planetary migration. During this process, any planets interior to such an orbit would…