Under the Sea – A Cepheus Mosaic

This was a very large work for me. Seven panels shot over two years in true color revealing a fascinating dusty swath of the Cepheus Flare molecular cloud complex. The Flare is a hotbed of star formation, young stellar objects (YSOs), emission regions, dark clouds, and even supernova remnants.

This image required more than 350 hours of exposure time. The number of distinct, catalogued objects in the field is rather daunting, but I’ll do my best to describe them in at least some small amount of detail. And although the overlay (selected by clicking the eye icon in the tool ribbon) points out these objects, I’ll include low-resolution crops below to help locate them.

At the top of the frame, you can find LBN 558, LDN 1251, and LDN 1243, collectively referred to as the Rotten Fish Nebula. Estimates place it at a distance of approximately 1,000 light years.

Moving down and to the left side of the frame, you can find the small blue reflection nebula vdB 157. It lies about 1,200 light years away.

Moving directly to the right of vdB 157 sits LDN 1235, the Shark Nebula. Another dark, cold star-forming region, the Shark is about 15 light years in breadth and is approximately 650 light years away.

Just behind the Shark’s head, you can see the blue reflection nebula catalogued as vdB 150. Directly below it is another reflection nebula catalogued as vdB 149. Hot, large blue stars illuminate each of these.

Moving downward in the frame, you can see a larger blue blob enclosed in a red shroud. This object is classified as Dengel-Hartl 5 and as PK 111+11.1. For decades, scientists believed it to be a planetary nebula because of the presence of a white dwarf star (WD 2218+706) in its midst. But further study has cast doubt on that—positing that it is a Strömgren sphere, that is it is merely gas and dust in the interstellar medium that the white dwarf is ionizing as it passes through it 1,300 to 1,600 light years away.

Directly adjacent to Dengel-Hartl 5 on the right is Barnard 175—a lanky, dark, dusty molecular complex 1,400 light years distant that is commonly called Wolf’s Cave. German astronomer Max Wolf’s assistant, August Kopff, discovered it in 1908. Through his early 20th-century optics, Wolf thought it looked like a cave and started calling it the Cave Nebula.

Later imaging and study has shown this to be an aberration, but the name Wolf’s Cave stuck. Coursing through the area, the band of red is ionized hydrogen gas that is part of an ancient supernova remnant (SNR 110.3+11.3). At the top of Barnard 175 sits the bright blue reflection nebula vdB 152. This, to me, looks like a penguin’s head. Between it, the Rotten Fish, and the Shark, my Antarctic sea analogy comes together. (Note that the crop is rotated 180 degrees).

Finally, near the bottom-center of the frame, you can see the Toast Nebula (LBN 532). Notice that the penguin has his eye on that tasty feast. There’s not a lot of information out there about LBN 532, but it appears that the consensus is that as part of the Cepheus Flare, it’s about 1,300 to 1,400 light years from us.