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Astrophotography

Sh2-119, The Clamshell Nebula
Author Last Post
Another amazing exposure of our Universe. Very nice detail.

Johnny B

Sent from my iPhone

I like this one. Not seen it before 
Aubrey 


Very nice. Never heard of this one
 

This is a fairly infrequently imaged emission nebula Sharpless-2 119, often overlooked because of the much brighter Sh2-117, the North America Nebula nearby, the edge of which can be seen at the bottom of the image. It is overwhelmingly Hydrogen-alpha but does have, as is shown here, some Sulfur II, and Oxygen III emission, that mainly around its primary energy source, 68 Cygni (SAO 50690, HD 203064). 68 Cygni is approximately 690 parsecs or 2,300 light-years distant, a hot blue giant of spectral type O7.5IIIn((f)), ~mag 5.0 (it is a variable), a young, massive star on the way to becoming a supergiant. The star is surrounded by a ring-shaped nebula (Sh2-119), likely a Strömgren Sphere, like the Rosette Nebula.


Although the star is visible to the naked eye, it was first cataloged by John Flamsteed, who named it Alpha Cygni. It was later named "68 Cygni" by Joseph Jerome de Lalande because it is the 68th visible star in Cygnus by right ascension in Cygnus, in his revision and correction to the Flamsteed Catalogue. Notably, during this revision, Lalande noted a star of questionable and apparently shifting location that later was "discovered" to be Neptune.


Another object worthy of note in this image is the small planetary nebula PK 87-3.1 seen in this image just to the left of and slightly down from 68 Cygni.


Equipment: Askar V modular telescope in its 80mm,600mm focal-length configuration, ZWO ASI2600MM_Pro camera w/7-position EFW, EAF focuser, AM5 Mount, ASI 120mm mini guide scope, and ASI 120MM guide camera. All controlled with a scope-mounted ASIAIR+ computer and an iPad Mini.


Processing in PixInsight with touchup in Adobe Lightroom Classic. Again, I have left the colors largely in the Hubble Palette but have boosted the Sulphur II and Oxygen III frequencies (red and blue) by about 20% each in the area of the nebulosity.

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