The planetary nebula NGC 246 in Cetus. POSS/DSS photo.

Although NGC 246 has a fairly low surface brightness, with dark skies, a nebula filter and patience, this planetary nebula is a fascinating sight in medium to large amateur scopes.

The nebula is just over four arc-minutes across and is slightly oval. The appearance is that of a thin, slightly oval annulus impounding a fainter glow. The annulus appears broken on the southeast side, but brighter on the west side. Toward the northeast, the glow appears bright, but diffuse. Involved in the nebula are three bright stars and a fainter one. The central star, at magnitude 12, should be visible in six-inch or larger scopes. Nebular filters definitely help improve detail in this object. I found both a UHC and OIII filter helpful, with the OIII having the definite edge.

While in the area, be sure to check out NGC 255, a 12th magnitude galaxy less than half a degree north. You should be able to corral both objects in the same field of view at low power. Not terribly impressive, NGC 255 appears as a bright glow elongated north-south.

(left) NGC 246 and the galaxy NGC 255, only half a degree north. (above) NGC 255. POSS/DSS photos.

How to get there:

NGC 246 is located about six degrees north of Beta Ceti.

Finder chart for NGC 246