Abell 39 is a planetary nebula in Hercules located at RA 16hr 27m 34s and DEC +27d 54m 33s. It is 6 light years across with a bright rim ~0.3 light years wide and is 7,000 light years distant. It has low surface brightness and strongly emits OIII and weakly H-a. It is almost perfectly circular, but its central blue mag 15.4  proginator star is not perfectly centered within the sphere for reasons unknown.  It is estimated that is has been expanding for about 22,000 years. North is toward the lower right and the image is about 34' x 34'.  There is some patchiness in the central region.  The lowest "star" within the nebula is not actually a star, but rather a distant galaxy, which can be seen more clearly in the NOAO image from WIYN 3.5 meter telescope at Kitt Peak.

This image is a composite of 3 nm Astrodon OIII and H-a narrowband filters, and Generation 2 RGB for star colors.  The system was guided with an SBIG ST-402 CCD on an Astrodon MonsterMOAG.  Data were collected automatically using CCDAutoPilot4 running MaximDL4.62 and Pinpoint.  Data were calibrated, registered and initially processed in CCDStack2.  Final processing was completed in PixInight and Photoshop CS5.