|Abell 39: Planetary Nebula (Hercules) RA: 16h 27.6m / DEC: +27° 54'.6|
Instrument: 10-inch Starfinder
Abell 39 is a faint little stinker. In fact, I almost logged this as a non-observation. However, this delicate planetary nebula emerges from hiding with the application of a Lumicon OIII or UHC filter. The sketch at left renders the view in my 10-inch Starfinder Newtonian at the moderate magnification produced by a 13.8-mm (82X) Meade SWA eyepiece outfitted with the OIII filter. The best description I've heard was by an observing companion who uttered, "That's [expletive deleted] faint." The circular planetary covers a 3' diameter with the east-southeast edge appearing just a tad brighter than the remaining perimeter. Abell 39 is bounded to the south by a trio of moderately bright stars. A 9th magnitude GSC star stands 15' due south. A similarly bright star resides 14' to the southwest. Tenth magnitude GSC 2052:587 lies about 13' to the east-southeast. This star has a 12th magnitude partner just 1'.5 to the southeast. 2.8 mag. Zeta (40) Herculis 4.7 degrees north-northeast.
|Instrument: 18-inch Obsession|
In the 18-inch Obsession at 122X (17-mm Nagler T4), Abell 39 appears a ghostly 3' diameter glow. The central star is plainly visible in the sketch at left. A triangular asterism of 14th and 15th magnitude stars lies immediately to the west. Among the other 20 stars peppering the field, the faintest simmer at mid-15th magnitude.
Layout, design & revisions © W. D. Ferris
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Revised: July 9, 2005 [WDF]