| Planetary
Nebula
aka PNG 100.6-05.4, PK 100-05.1, ARO 85 RA: 22h23m55.7s Dec: +50°58'00" (Lacerta) Integrated Visual Magnitude: 12.6 Angular Diameter: 7" Mean Surface Brightness: 16.4 Mag/arc-sec² Distance 9400 ly Minimum requirements to detect: 6-inch scope under dark skies |
IC 5217 is an often overlooked planetary nebula in Aquarius. This tiny 12.6 magnitude object subtends a mere 6". It has a very high surface brightness but is very small. A six-inch will show the nebula as a faint star that looks slightly non-stellar. Look for a greenish hue. Larger apertures and high magnifications are required to see detail.
In "Summertime Planetaries Beyond the NGC" (August 1999, Sky & Telescope) Jay McNeil said of IC 5217, "On a night of particularly steady seeing, I pumped up the power to 855x and saw a bright inner disk with an obvious north-south elongation."
In my 18-inch at 95x it appeared stellar, but the eerie green color made it stand out. At 250x, it appeared as a tiny, bright oval. Even at 430x it was still quite small, green, and bright. The best view came at 860x, where it took on the appearance of a little saturn nebula (at least as seen in some photographs). It appeared distinctly oval and left the impression of little "handles" sticking out of either end. This planetary blinks dramatically with any eye movement at this magnification.
Be sure to note the nearby star chain (to the lower left of the nebula in the chart below).
The field in an 6-inch f/8 at 50x. North is down and east is to the right.
| Millennium
Star Atlas Vol III Chart 1103
Sky Atlas 2000 Chart 9 Uranometria 2000 Vol I Chart 57 Herald-Bobroff Astroatlas B-05 C-03 |
