Particles Co-orbital to Janus and to Epimetheus: A Firefly Planetary Ring

Othon C. Winter, Alexandre P. S. Souza, Rafael Sfair, Silvia M. Giuliatti Winter, Daniela C. Mourão, Dietmar W. Foryta
2017 Astrophysical Journal  
The Cassini spacecraft found a new and unique ring that shares the trajectory of Janus and Epimetheus, co-orbital satellites of Saturn. Performing image analysis, we found this to be a continuous ring. Its width is between 30% and 50% larger than previously announced. We also verified that the ring behaves like a firefly. It can only be seen from time to time, when Cassini, the ring and the Sun are arranged in a particular geometric configuration, in very high phase angles. Otherwise, it
more » ... "in the dark", not visible to Cassini's cameras. Through numerical simulations, we found a very short lifetime for the ring particles, less than a couple of decades. Consequently, the ring needs to be constantly replenished. Using a model of particles production due to micrometeorites impacts on the surfaces of Janus and Epimetheus, we reproduce the ring, explaining its existence and the "firefly" behavior.
doi:10.3847/1538-4357/aa9c7f fatcat:pm6aqjfiorhmxlzba7umppo7ja