Uranus' rings

In stark contrast to Saturn's rings, the main rings of Uranus are comprised of extremely narrow ringlets. All of the rings are under 10 km wide with the exception of the outermost epsilon ring, which is still under 100 km across. Several of the rings are also significantly eccentric and inclined. While it is hypothesized that the shepherd moons Cordelia and Ophelia, who straddle the epsilon ring, can keep the epsilon ring radially confined it is unclear what keeps the other rings from spreading out radially over time. The Uranus system was only visited by spacecraft once, during the Voyager 2 flyby in 1986. Thus, the majority of ring data we have has been obtained from the ground.

Ground-based stellar occultations of the rings provide us with precise measurements of the rings' radial locations at several different longitudes and times. My work is focused on finding patterns in the radially positions of the rings to look for connections with external forces. See the Press page for more details about my published works related to the Uranian rings.

The above diagram shows the result of a stellar occultation observation. As we measure the light from a star occulted by Uranus, we see drops in the starlight intensity before and after Uranus itself blocks the light of the star. These narrow drops in starlight intensity are in fact the rings briefly blocking the light from the star. Figure credit: from James Elliot's Stellar Occultation Studies of the Solar System (1979) Annual Reviews of Astronomy and Astrophysics. He was the leader of the team who discovered the rings of Uranus in 1977 using this method while aboard NASA's Kuiper Airborne Observatory flying into the shadow of Uranus above the Indian Ocean west of Australia.