The λ ring was one of two rings discovered by "Voyager 2" in 1986. It is a narrow, faint ring located just inside the ε ring, between it and the shepherd moon Cordelia. This moon clears a dark lane just inside the λ ring. When viewed in back-scattered light, the λ ring is extremely narrow—about 1–2 km—and has the equivalent optical depth 0.1–0.2 km at the wavelength 2.2 μm. The normal optical depth is 0.1–0.2. The optical depth of the λ ring shows strong wavelength dependence, which is atypical for the Uranian ring system. The equivalent depth is as high as 0.36 km in the ultraviolet part of the spectrum, which explains why λ ring was initially detected only in UV stellar occultations by "Voyager 2". The detection during a stellar occultation at the wavelength 2.2 μm was only announced in 1996.