Neptune's "Partial Rings" (or "Ring Arcs")

Caption NASA originale:"One of two new ring arcs, or partial rings, discovered by NASA's Voyager 2 spacecraft, is faintly visible here just outside the orbit of the Neptunian moon 1989N4, also discovered by Voyager 2.
The 155 second exposure taken by Voyager's narrow-angle camera shows the glare of an overexposed Neptune to the right of the moon and ring arc.
The two bright streaks below the moon and ring arc are stars.
The ring arc is approximately 50.000 Km (or 30.000 miles) long".