M 57 (NGC 6720, PK 63+13.1) Planetary Nebula in Lyra

Located at: RA 18 hours 53 minutes 35 seconds, Dec +33 degrees 01 minutes 44 seconds

Size: 1.8' x 1.4' Magnitude: 9.7 photographic Class: 4+3

North is up

West to the right

Telescope:

Celestron 11 operating at approximately f10

Camera:

 ST-8XME, self-guided, binned 1x1, temp -15c, camera control MaxIm DL 4.1

Image:

 No filter, 80 minutes (16 x 5 minute subs), 10/2/2005

Processing:

 CCDStack 1.2, Photoshop 7.0

Location:

 Rolling Roof Observatory, Thousand Oaks, CA 91360 (+34d 13m 29s -118h 52m 20s)

Notes:

One of the few C11@ f10 images to come out half way decent. The 16 sub exposures were not well guided, but by aligning,  combining and processing, I was able to get this result. Seeing was about 3-4 arc seconds. See the 14.5" f5 image.

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 6720

NGC 6720 = PK 63+13.1 = M57 = Ring Nebula = PN G063.1+13.9
18 53 35.1 +33 01 45
V = 8.8;  Size 86"x63"

18" (6/21/03): Observed the Ring at very high powers for the first time with the 
Zambuto Starmaster and tracking in steady seeing.  Using the 2.5x Powermate, I 
used 538x, 807x and finally 1087x!  At 538x and 807x, the central star flicked 
on and off several times, but only momentarily.  At 1087x, the central star was 
visible more consistently, flickering on/off regularly and cleanly visible for a 
few seconds at a stretch.

17.5" (6/5/99): Viewed under very steady seeing at 380x.  The halo is elongated 
4:3 WSW-ENE and clearly brighter along the north and south sides (minor axis).  
The ends of the major axis are clearly "thinner" and slightly fainter at the 
following end. The interior has a pale gauzy appearance.  The edge of the ring 
has a "wooly" appearance with a strong impression of small irregular wisps or 
filaments hinting at the extremely faint outer halo.  The central star popped in 
and out of view a few times.  A mag 13 star is close off the east side and a 
very faint mag 15.7 star is a similar distance off the west end.  Another mag 
15.6 star is 1' due south of center.  At high power a 3" pair of mag 14-15 stars 
~1.3' NNW of center are just resolved with a difficult mag 16.1 star ~30" 
further north.  On 8/6/02 did not see the mag 16.6 star on the visual sequence 
chart.

17.5" (7/1/89): extremely faint central star visible for moments at 412x just E 
of center.  The central star was held steadily for a few seconds at best with 
averted vision.  Forms an unusual pair with the extremely faint galaxy IC 1296 
4' NW.

13": very bright, moderately large, slightly elongated WSW-ENE, high surface 
brightness, best example of annularity although interior not dark.  Slightly 
fainter at ends of major axis.  Central star not seen.

- by Steve Gottlieb