New Dust Belts of Uranus: One Ring, Two Ring, Red Ring, Blue Ring
Imke de Pater,1*
Heidi B. Hammel,2
Seran G. Gibbard,3
Mark R. Showalter4
We compared near-infrared observations of the recently discovered outer rings of Uranus with Hubble Space Telescope results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced by impacts into the embedded moon Mab, which apparently orbits at a location where nongravitational perturbations favor the survival and spreading of submicron-sized dust. R/2003 U 2 more closely resembles Saturn's G ring, which is red, a typical color for dusty rings.
1 Astronomy Department, 601 Campbell Hall, University of California, Berkeley, CA 94720, USA.
2 Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA.
3 Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
4 SETI Institute, 515 North Whisman Road, Mountain View, CA 94043, USA.
* To whom correspondence should be addressed. E-mail: imke{at}astron.berkeley.edu
