NGC6888 The Crescent Nebula with
 PN G75.5+1.7 The Soap Bubble Nebula

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 from Earth. It was discovered by Friedrich Wilhelm Herschel in 1792.[2] It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000[3] to 400,000[citation needed] 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.


It is a rather faint object located about 2 degrees SW of Sadr. For most telescopes it requires a UHC or OIII filter to see. Under favorable circumstances a telescope as small as 8 cm (with filter) can see its nebulosity. Larger telescopes (20 cm or more) reveal the crescent or a Euro sign shape which makes some to call it the "Euro sign nebula".


The Soap Bubble Nebula, or PN G75.5+1.7, is a planetary nebula in the constellation Cygnus, near the Crescent Nebula (NGC 6888).Adrift in the rich star fields of the constellation Cygnus, this lovely, symmetric nebula was only recognized a few years ago and does not yet appear in some astronomical catalogs. In fact, amateur astronomer Dave Jurasevich identified it as a nebula on 2008 July 6 in his images of the complex Cygnus region that included the Crescent Nebula (NGC 6888). He subsequently notified the International Astronomical Union. Only eleven days later the same object was independently identified by Mel Helm at Sierra Remote Observatories, imaged by Keith Quattrocchi and Helm, and also submitted to the IAU as a potentially unknown nebula. The nebula, appearing near the bottom left of the image above, is now known as the Soap Bubble Nebula.


This image was taken on the nights of 26,28 September and 2nd and 10th of October 2016 through my Megrez 90 refractor with 0.8x focal reducer and Atik 460EX CCD camera with Astrodon 3nm filters. It consists of 50 x 600s in OIII and 33 x 600s in Ha. The soap bubble was not visible in any of the subs, only when stacked and processed.

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