NGC 6781 (PK 41-2.1) Planetary Nebula in Aquila
Located at: RA 19 hours 18 minutes 28 seconds, Dec +06 degrees 32 minutes 15 seconds
Size: 1.8'; Magnitude: 11.8 photographic; Class: 3+3
North is up

West to the right
| Telescope: |
8" f5 Newtonian reflector |
| Camera: |
ST-8XME, self-guided, binned 1x1, temp -20c, camera control MaxIm DL 4.55 |
| Image: |
Red (Hoya 25A) filter, 150 minutes (15 x 10 minute subs), 08/25/2006 |
| Processing: |
CCDStack 1.1, Photoshop 7.0 |
| Location: |
Rolling Roof Observatory, Thousand Oaks, CA 91360 (+34d 13m 29s -118h 52m 20s) |
| Notes: |
This is another rather small object for my 1000mm focal length, like M 1. From the NGC / IC Project: Contemporary Visual Observation(s) for NGC 6781 NGC 6781 = PK 41-2.1 = PN G041.8-02.9 19 18 28.2 +06 32 23 V = 11.6; Size 111"x109" 18" (8/14/04): at 225x, appears moderately bright, fairly large, round, at least 1.5' diameter. A mag 13.5 star is at the NE edge of the rim with a fainter star off the NNW edge. The rim is clearly brighter, particularly along the entire south side, with the rim fading on the north side giving an asymmetric or crescent appearance. A large central "hole" appears slightly darker. At 160x, one or possible two extremely faint stars flickered on and off within the interior of the disc but did not appear to be the central star . 17.5" (6/30/00): at 220x unfiltered this fairly bright PN has a 1.5' round halo. The rim is brightest and more well-defined along an arc on the S and SE rim. The central 45" hole is slightly darker and irregular in surface brightness. A mag 13 star is at the NE edge and once or twice I caught a fainter glimmer of an interior star north of center. 17.5" (7/12/99): at 100x appears fairly bright, round, ~1.6' diameter with a darker center. I used a variety of magnifications and filters but the most interesting view was at 220x using a UHC filter. With this combination the PN is slightly elongated E-W and clearly brighter along the southern rim with the brightening tapering towards the ends so this brighter portion had a crescent appearance. Because of this asymmetric rim the darker center seems offset and only weakly brightens at the NW rim. A mag 13 star is just off the NE edge 1' from center. 17.5": at 222x and UHC filter; very large, about 1.8' diameter, much brighter on the SW portion of the rim, darker center. A mag 13 star is just off the NE edge. 13": brighter rim mainly on the SW side, slightly annular appearance. A faint star is off the E edge. - by Steve GottliebHistorical Research Notes / Correction for NGC 6781 NGC 6781. The position is for a very faint, very blue star -- the southeastern of two -- near the geometric center of the planetary. The star is not seen at all in any of the 2MASS images, but is clear on the DSS2B image. - Dr. Harold G. Corwin, Jr. |