NGC6888 The Crescent Nebula and friend in Ha ! (WIP)

[TakMan]

NGC6888 The Crescent Nebula and the Soap Bubble Nebula, PN G75.5+1.7 (in Ha)

This image contains the Crescent Nebula NGC 6888 and surrounding nebulosity belonging to the γ Cygni Nebula Region.

The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5000 light years away and around 25 light years across.

It was discovered by Friedrich Wilhelm Herschel in 1792. Although it looks like a miniature version of the well-known Veil Nebula, NGC 6888 is neither a supernova remnant nor a planetary nebula, but one of the rare Wolf-Rayet nebulae (another being 'Thor's Helmet').

It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163 - the bright star located centrally within the nebula). These stars rank among the most massive and hottest stars known. A major characteristic of Wolf-Rayet Stars are their strong stellar winds, approximately 2.000 kilometers per second, and the enormous mass-loss associated with them, they can lose an entire solar mass in only 10.000 years.

It is the interaction of these super-fast winds colliding that produces this striking nebulae - energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago. The result of the collision is a shell and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures.

Wolf-Rayet stars and their nebulae are short-lived phenomena (in astronomical timescales), these stars will erupt in supernovae during the next million years.

The surrounding area contains several patches of emission nebulosity. The brightest parts are designated LBN 215 (upper left), LBN 208 (upper central region and to the right, filamentary structure) and LBN 193 (lower right) in Lynd's Bright Nebulae catalogue.

The Soap bubble nebula, or PN G75.5+1.7, is a planetary nebula near the Crescent Nebula (see left). It was only recently discovered by amateur astronomer Dave Jurasevich using an Astro-Physics 160 mm refractor telescope who imaged the nebula on June 19, 2007 and on July 6, 2008.

Image Details:

Just 5x 1200sec subs, more to follow (hopefully)...

Takahashi FSQ106-ED + dedicated F/R @f/3.6 SBIG STF8300M + Baader 7nm Ha filter

Guided with an SBIG ST-i and Skywatcher ST-80 via MicroProjects Equinox Image

Takahashi EM400 mount - controlled via MicroProjects Equinox Pro (all on a Intel 17" Apple MacBook Pro)

Preprocessed (Darks and Flat frames), aligned and stacked in Nebulosity 3.

Processed in Adobe Photoshop CS5 with 'Noel's Actions'

Hi-res via Astrobin here: http://astrob.in/full/41453/

Thanks for looking,

Damian

[Coco]

The high res is a treat ... superb!

Get that 106 on some galaxies Damian, its such a short season... it seems like last month the Cygni region was just setting for the end of Autumn/Winter ..

[Martin-Devon]

Damian, that's a great image, really nice detail coming through. I like also the information you provide on the target, we don't often see this, but it adds a lot to the package. Great work.

Martin

[Gina]

Great image - lovely detail

[Mark72]

Great result Damian,

Thanks also for detailed description.

Mark

[TakMan]

Thanks all....

Glad the description added was of interest - pulled from various sources off the net!

Damian

[ollypenrice]

Tremendous sense of foreground/background when seen framed like this.

O111 is astounnding on the Crescent, too, because it catches an outer envelope.

Splendid!

Olly

[swag72]

I love the detail on this and the soap bubble is clearly visible - A superb image.

[Superdavo]

Wow!