The Brightening of Saturn's F Ring
arXiv:1408.2536 · doi:10.1016/j.icarus.2012.02.020
Abstract
Image photometry reveals that the F ring is approximately twice as bright during the Cassini tour as it was during the Voyager flybys of 1980 and 1981. It is also three times as wide and has a higher integrated optical depth. We have performed photometric measurements of more than 4,800 images of Saturn's F ring taken over a five-year period with Cassini's Narrow Angle Camera. We show that the ring is not optically thin in many observing geometries and apply a photometric model based on single-scattering in the presence of shadowing and obscuration, deriving a mean effective optical depth tau = 0.033. Stellar occultation data from Voyager PPS and Cassini VIMS validate both the optical depth and the width measurements. In contrast to this decades-scale change, the baseline properties of the F ring have not changed significantly from 2004 to 2009. However, we have investigated one major, bright feature that appeared in the ring in late 2006. This transient feature increased the ring's overall mean brightness by 84% and decayed with a half-life of 91 days.
arXiv comment27 pages, 12 figures, 2 tables
References in corpus (3)
Cited by in corpus (9)
- Saturn's G and D rings provide nearly complete measured scattering/phase functions of nearby debris disks
- A Survey of Low-Velocity Collisional Features in Saturn's F Ring
- Bright clumps in the D68 ringlet near the end of the Cassini Mission
- Analysis of Clumps in Saturn's F Ring from Voyager and Cassini
- The Vertical Structure of the F Ring of Saturn from Ring-Plane Crossings
- A curious ringlet that shares Prometheus' orbit but precesses like the F ring
- Changes in a Dusty Ringlet in the Cassini Division after 2010
- Examining Uranus' zeta ring in Voyager 2 Wide-Angle-Camera Observations: Quantifying the Ring's Structure in 1986 and its Modifications prior to the Year 2007
- A simple model for the location of Saturn's F ring