Abstract

All the giant planets in our Solar system have rings and moons in orbit around them, and act as a fossil record of their formation. Despite the large numbers of detected extrasolar planets, though, no Saturn-like rings have yet been observed.

In May 2007, a young star (called J1407 ) underwent a complex series of fluctuations in brightness lasting over two months. At one point, the star dimmed by over 95% over a few hours. We have modelled this light curve as a giant, highly structured ring system that is hundreds of times larger than Saturn’s rings orbiting around an unseen substellar secondary companion, J1407b.

This is the first detection of exorings around an astronomical object outside our Solar system, and the structure of these rings suggests the formation of moons around J1407b. I will talk about our model and the potential for seeing more of these eclipses in the future.