A barred spiral with a hidden ring — IC 5092 in Pavo
IC 5092 is a barred spiral galaxy in the constellation Pavo, about 141 million light-years from Earth.
It is classified as (R’)SB(rs)c, showing a luminous central bar, loosely wound spiral arms, and a faint pseudoring structure. With an apparent size of 2.9′ × 2.3′, the galaxy spans roughly 125,000 light-years across, nearly the size of the Milky Way.
Delicate dust lanes mark the bar and arms, while bluish knots highlight areas of active star formation. The faint outer pseudoring visible in the image is not a true ring, but the result of spiral arms wrapping back on themselves under the bar’s influence. At these resonance zones, gas streams accumulate and ignite new star formation, giving the illusion of a continuous loop.
Astronomers have found that such pseudorings are fairly common in barred spirals. They often form near the outer Lindblad resonance — a region where the orbital motion of stars and gas falls into step with the bar’s rotation pattern. In these zones, material tends to pile up into arcs or loops, shaping the galaxy’s outer profile.
IC 5092 stands as a clear example of this process, where bar dynamics and spiral structure combine to create the illusion of a cosmic ring.
Imaged in LRGB on my Planewave CDK 1000 at Observatorio El Sauce, Chile.
Image acquisition and processing: Mike Selby