As the northern hemisphere moves into late spring, the Milky Way comes into view before midnight. And that means all those wonderful nebulae are now ready for their closeups!

This one is Sharpless 112 (Sh2-112), an emission nebula in Cygnus. Specifically it’s the bright, circular region near the center. But, it’s clear that this is just one small part of a much larger cloud of gas. It just happens to be heavily radiated and so glows much more brightly.

My goal for this image was to show how the bright nebula was not this isolated thing but was really embedded in a much larger thing. Thankfully, modern cameras and processing techniques make that a possible though still challenging task.

I don’t want to read too much interpretation into the image but it looks like that bright star embedded int he cloud has blasted out an opening and the glow we see is from interior gas in the cloud. It can be challenging to take a two dimensional image like this and be sure our visual three dimensional interpretation reflects reality but that’s the way my brain is seeing this.

This image puts the sulfur in red, hydrogen in green and oxygen in blue so you can make some interpretation about the contents of the gas by the colors here. Yellowish colors imply both sulfur and hydrogen. Bluish colors imply oxygen. However, you can’t make assumptions about their relative abundance from the image. In reality hydrogen dominates and to compensate for that the oxygen and sulfur images are more strongly stretched to help show where they occur. If that hadn’t been done then the image would be overwhelmingly green.

As to Sh2-112 itself…there isn’t much I can say.

For all the technical details see astrobin.