Messier 17–A new astrophoto from last week, is technically viewable from the north but so much better when straight overhead! The last time I imaged this was about 4 years ago and I wasn't nearly as good at processing my images in the computer after taking them so this one was due for an update.
M17 has a bunch of popular names: the 'Checkmark' Nebula, the 'Omega Nebula', Swan Nebula, Horseshoe Nebula and the Lobster Nebula; popular with Southern Hemisphere viewers I'm told.
M 17 is located in the rich star fields of the the Milky Way in Sagittarius; very much in the direction of the center of our Milky Way galaxy, although it's only about one third of that distance from us. It can be found easily in telescopes and even binoculars, along with its close neighbor, M 16, the Eagle Nebula, the center of which was featured as the famous Hubble photo, "The Pillars of Creation".
This is a great object even in very small telescopes because the main part of it is concentrated and bright. But because of the richness of the starfields when looking this direction there is a lot of extended detail in the object and a bunch of cool stuff floating nearby.
It is considered one of the brightest and most massive star-forming regions of our galaxy. Its local geometry is similar to the Orion Nebula except that it is viewed edge-on rather than face-on.
The open star cluster NGC 6618 lies embedded in the nebulosity and causes the gases of the nebula to shine due to radiation from these hot, young stars; however, the actual number of stars in the nebula is much higher – up to 800, 10% of which are the two brightest kinds of stars plus over a thousand stars in formation in its outer regions. It is also one of the youngest clusters known, with an age of 'just' 1 million years.
The overall color of the Omega Nebula is reddish, due to light emitted from the hot hydrogen gas excited by the stars that have just formed within it. However, the nebula's brightest region is actually white, apparently the result of light emission from the hottest gas, mixed with reflections of bright starlight from dust. The overall nebula contains a large amount of dark obscuring material, which has been heated by the hidden young stars, and shines brightly in the infra-red.
Distance estimates for M 17 range between 5,000 and 6,000 light years - a little less than its apparent neighbor, M 16 the Eagle Nebula. Physically, these two star forming regions are indeed close together, in the Sagittarius-Carina spiral arm of the Milky Way galaxy, and are perhaps part of the same giant complex of interstellar matter.
While the visible nebula is about 15 light-years across, the total gaseous cloud, including low-luminosity material, extends to at least 40 light-years.
Normally I would crop an image like this to really feature the main part of the nebula but as I was processing the image I kept noticing all the really cool, dark, dusty stuff in the outlying regions of this object and just had to keep a version that was nearly the camera's full frame to get some of that context around it.
Pretty much the full camera frame, about four degrees of sky.
Here’s some of that wispy dark detail…