NGC 1232 — Galaxy in Eridanus

NGC 1232 is a beautiful face-on grand-design barred spiral in Eridanus, about 60 million light-years away. Multiple bright spiral arms wind outward from a small bar, threaded by dust lanes and dotted with HII regions and young blue star clusters. A small companion, NGC 1232A, appears as a separate distorted dwarf to the southeast and is gravitationally connected to the main galaxy through a faint stellar bridge. At magnitude 9.9 with about 7 arcminutes diameter, NGC 1232 has reasonable surface brightness for a face-on Sc and is one of the more rewarding spirals in southern Eridanus.

A 4-inch telescope from a dark site shows a soft round glow with a small concentrated nucleus. An 8-inch at 150x reveals an oval halo with a brighter middle and hints of mottling in the surrounding disk. A 12-inch under good skies begins to bring out asymmetries that suggest the spiral arms, though resolving the arms themselves usually requires imaging. NGC 1232 lies at declination -20 degrees, a moderate-altitude object from the southern half of the United States and southern Europe. Best observed October through February.

Discovered by William Herschel on 20 October 1784. NGC 1232 has become a popular VLT showpiece target since the late 1990s — the European Southern Observatory's deep colour images of the galaxy are widely reproduced in textbooks and outreach materials.