The Dumbbell Nebula (also known as Apple Core Nebula, Messier 27, or NGC 6853) is a planetary nebula in the constellation Vulpecula, at a distance of about 1,360 light years.

This object was the first planetary nebula to be discovered; by Charles Messier in 1764. At its brightness of visual magnitude 7.5 and its diameter of about 8 arcminutes, it is easily visible in binoculars, and a popular observing target in amateur telescopes.

The Dumbbell Nebula appears to be shaped like an prolate spheroid and is viewed from our perspective along the plane of its equator. In 1992, Moreno-Corral computed that its rate of expansion in the plane of the sky was no more than 2.3" per century. From this, an upper limit to the age of 14,600 yr may be determined. In 1970, Bohuski, Smith, and Weedman found an expansion velocity of 31 km/s. Given its semi-minor axis radius of 1.01 ly, this implies that the kinematic age of the nebula is some 9,800 years.

Like many nearby planetary nebulae, the Dumbbell contains knots. Its central region is marked by a pattern of dark and bright cusped knots and their associated dark tails. The knots vary in appearance from symmetric objects with tails to rather irregular tail-less objects. Similarly to the Helix Nebula and the Eskimo Nebula, the heads of the knots have bright cusps which are local photo-ionization fronts.

The central star, a white dwarf, is estimated to have a radius of 0.055 ± 0.02 R☉ which gives it a size larger than any other known white dwarf. The central star mass was estimated in 1999 by Napiwotzki to be 0.56 ± 0.01 M☉. [Source Wikipedia].

The image was captured with the Meade 12"LX200, using the Atik 383L+ mono at F7.16. Astronomik's RGB filters were used for the color mix. The Ha and OIII filters for luminance. All subs were taken at 1x1 bin, -10C, and 10 minutes each.

Ha : 26 subs (4.33 hr) on Jul 24th, Jul 25th and Jul 27th.

OIII : 27 subs (4.50 hr) on Jul 27th and Aug 2nd.

SII : 25 subs (4.17 hr) on Aug 3rd and Aug 4th. (this data was not used)

Red : 6 subs (1.00 hr) on Aug 7th.

Green : 6 subs (1.00 hr) on Aug 7th.

Blue : 6 subs (1.00 hr) on Aug 7th.

Processing was done with PixInsight, following (for the most part) kayronjm's tutorial of Feb. 24th

North is up. This is a very slight crop.

Image A: Integrated monochromatic of all the Ha subs. (Note 1)

Image B: Integrated monochromatic of all the O3 subs. (Note 1)

Image C: Bicolor combined image of Ha and O3 per the following formula -- (Note 1)

Red = O3, Grn = 0.5O3 + 0.5Ha, Blu = Ha

Image D: Combined "extracted" Luminance from Image no. 3, with RGB. (Note 2)

Image E: Similar to Image D, but with OIII only, No Ha. (Note 2)

It can be seen from this one (more eye pleasing) that the "blochy-ness" of Image D is predominantly from the Ha contribution.

My goal was to capture some of the faint nebulosity surrounding the nebula, and in that sense the effort was successful. This feature can be seen in very fine detail in all of the images, especially the mono Ha and O3 images. Unfortunately the color images, while retaining good detail, just don't have the snap I was hoping to get. The last image - Image D - (including the RGB data) is particularly blotchy and lacks subtlety. I will continue to work on this target and see if I can improve it. [See Image E for some improvement].

I am using a trial version of Sequence Generator Pro, and most of the camera control was done with this software (as opposed to APT). This is also the maiden voyage of Starizona's MicroTouch AutoFocus system. It has worked well with SGPro, and I plan to move forward with both these tools.

NOTES:

1. Lost in ASTROBIN data loss catastrophe in early 2020

2. Replaced due to ASTROBIN data loss catastrophe in early 2020