| Planetary
Nebula
aka PNG 119.6-06.7, PK 119-06.1, ARO 18 RA: 00h28m15.0s Dec: +55°57'54" (Cassiopeia) Integrated Visual Magnitude: 13.3 Angular Diameter: 5" Mean Surface Brightness: 16.5 Mag/arc-sec² Distance 16000 ly Minimum requirements to detect: 6-inch under dark skies |
Humason 1-1 is a tiny planetary nebula in Cassiopeia. It has been reported to be brighter than the magnitude listed above, perhaps as bright as 12.4 magnitude, rendering it visible in a 6-inch scope. At least 130x is required to see its tiny, blue-green disk.
In my 18-inch f/4.5 Dob it appeared stellar at 97x. The best view came at 430x. At this magnification the elongated, uniformly illuminated disk was distinctly visible. I saw it as slightly greenish in color. What appeared to be a central star was intermittently visible, but the surface brightness of the "central bright spot" was only ever so slightly higher than that of the surrounding nebula.
The field in an 16-inch f/5 at 90x. North is down and east is to the right.
| Millennium
Star Atlas Vol I Chart 66
Sky Atlas 2000 Chart 1 Uranometria 2000 Vol I Chart 35 Herald-Bobroff Astroatlas B-05 C-04 |
