相关论文: Formation of the G-ring arc

We simulate the collision of precursor icy moons analogous to Dione and Rhea as a possible origin for Saturn's remarkably young rings. Such an event could have been triggered a few hundred million years ago by resonant instabilities in a…

Since 2004, Saturn Electrostatic Discharges (SEDs), which are the radio signatures of lightning in Saturn's atmosphere, have been observed by the Cassini Radio and Plasma Wave Science instrument (RPWS). Despite their important time…

The best constraints on the internal structures of giant planets have historically come from measurements of their gravity fields. These gravity data are inherently mostly sensitive to a planet's outer regions, providing only loose…

The Milky Way and Andromeda galaxy are each surrounded by a thin plane of satellite galaxies that may be corotating. Cosmological simulations predict that most satellite galaxy systems are close to isotropic with random motions, so those…

In this work, we model the radial density profile of the outer A ring of Saturn observed with Cassini cameras (Tiscareno & Harris 2018): An axisymmetric diffusion model has been developed, accounting for the outward viscous flow of the ring…

The recent discovery of narrow rings around minor bodies has raised many questions regarding their origin and current dynamics. Sharp ring boundaries seem indicative of shepherding moonlets, but none have been found. All rings lie close to…

Aegaeon (Saturn LIII, S/2008 S1) is a small satellite of Saturn that orbits within a bright arc of material near the inner edge of Saturn's G ring. This object was observed in 21 images with Cassini's Narrow-Angle Camera between June 15…

We present a review of Saturn's interior structure and thermal evolution, with a particular focus on work in the past 5 years. Data from the Cassini mission, including a precise determination of the gravity field from the Grand Finale…

Aims. To investigate the mid-infrared (MIR) characteristics of Saturn's rings. Methods. We collected and analyzed MIR high spatial resolution images of Saturn's rings obtained in January 2008 and April 2005 with COMICS mounted on Subaru…

The formation of Pluto's small satellites - Styx, Nix, Keberos and Hydra - remains a mystery. Their orbits are nearly circular and are near mean-motion resonances and nearly coplanar with Charon's orbit. One scenario suggests that they all…

Cassini radio science experiments have provided multiple occultation optical depth profiles of Saturn's rings that can be used in combination to analyze density waves. This paper establishes an accurate procedure of inversion of the wave…

Nowadays, astronomers want to observe gaps in exozodiacal disks to confirm the presence of exoplanets, or even make actual images of these companions. Four hundred and fifty years ago, Jean-Dominique Cassini did a similar study on a closer…

In this paper we address the following question: do the recent advances in the orbit determination of the major natural satellites of Saturn obtained with the analysis of the first data sets from the Cassini mission allow to detect the…

Transient spiral waves of moderate amplitude cause substantial changes to the angular momenta of many stars in a galaxy disk. Stars near to corotation are affected most strongly: for a wave of ~20% overdensity, the rms change for particles…

The spokes observed in Saturn's rings have been a subject of scientific debate since their discovery by Stephen J. O'Meara in the 1970s and their confirmation by the Voyager flybys in the early 1980s (Smith et al., 1982). While the Cassini…

A new theoretical hypothesis on the origin and formation of the solar and extrasolar planetary systems is summarized and briefly discussed in the light of recent detections of extrasolar planets, and studies of shock wave interaction with…

A chemical evolution model for the bimodal-like abundance distribution in the external galaxy M51 recently derived on the basis of HST data for more than a half million red supergiants is developed. It is shown that, like in our Galaxy,…

Star formation induced by a spiral shock wave, which in turn is generated by a spiral density wave, produces an azimuthal age gradient across the spiral arm, which has opposite signs on either side of the corotational resonance. An analysis…

Saturn is ringing weakly. Exquisite data from the Cassini mission reveal the presence of f-mode oscillations as they excite density waves in Saturn's rings. These oscillations have displacement amplitudes of order a metre on Saturn's…

Spiral arm structures seen in scattered light observations of protoplanetary disks can potentially serve as signposts of planetary companions. They can also lend unique insights into disk masses, which are critical in setting the mass…