Going Dark

It all began back in early June when I took a look at the globular star cluster known as Messier 9 in Ophiuchus. I didn’t realize it until I pointed my Unistellar eVscope there, but in the sky very near to M9 is a dark nebula, specifically the dark nebula known as Barnard 64 (The name comes from its entry into a catalog of dark nebulae compiled by Yerkes Observatory astronomer E.E. Barnard in 1919.).

Messier 9 (left) and Barnard 64 (upper right)

Sure, I realized that dark nebulae where out there. You can see them when you look at photos of the Triffid Nebula or the Lagoon Nebula (see my post on Messier Nebulae). The most famous dark nebula of them all is the Horsehead Nebula (Barnard 33)—a dark cloud that is silhouetted against a faintly glowing red emission nebula near the Belt of Orion.

B33, the Horsehead Nebula in Orion

 But to me Barnard 64 is something different than those examples. It’s a dark cloud that is blotting out the light of stars behind it and not a dark cloud seen in front of a bright one. Seeing Barnard 64 started me on a journey to look for more dark nebulae, so I thought I would share a few of the dark things that I’ve recently been looking at.

Also in the constellation of Ophiuchus is Barnard 72, commonly known as The Snake.

The photo above is a mosaic of images that I made with my Unistellar eVscope of The Snake (the big "S"), but also visible in the image are other dark nebulae. To the right of The Snake is Barnard 68 and below that is Barnard 69.

There are plenty of dark nebulae in other constellations too. The center of our Milky Way Galaxy lies in the direction of the constellation of Sagittarius where more members of Barnard's catalog can be found. 

The image above shows dark nebula Barnard 86 next to a small, brilliant open star cluster (NGC 6520). They make a striking contrast. That's a red giant star visible on the upper edge of the nebula. 

Finally, (for now) let me show you three more dark nebulae in Sagittarius.

There's a lot in this image. I made it by taking 11 different exposures to produce this mosaic that covers about 1.3 degrees x 0.9 degrees. 

The amazingly dense field of stars seen here on the left half of the image forms Messier 24, the Sagittarius "Star Cloud."  

In the lower left you'll notice a trio of bright stars. The topmost of those is a red giant star. To the right of the red giant is a hot blue star that is vastly more luminous than our Sun. Above the red giant is the open star cluster known as NGC 6603. Near the center there's another little cluster of stars known as Collinder 469. To the right of Collinder 469 is the dark nebula known as Barnard 92. Up and left from Barnard 92 is the somewhat squid-shaped Barnard 93. In the upper left of the image is the smaller Barnard 307. Barnard 307 is one of the many dark nebulae in Barnard's catalog that were added to an expanded version to the catalog that was published in 1927, several years after his death. 

I've got more dark nebulae on my list. Hopefully in the not too distant future I'll post images of some of them here.