The Dark Shark

18. Sep. 2025

Gear used

• Telescope: Samyang 135mm cameralens at f/2.8
• Camera: ZWO ASI2600MC pro
• Guidescope: Uniguide 32
• Guidecamera: ZWO ASI220MM Mini
• Mount: ZWO AM5N
• Controls: ASIAIR Plus

Data collected

• Sky: Bortle 4 to 5
• Lights: 292 x 180s
• Biases: 29
• Darks: 20
• Flats: 30

A New Challenge

The Dark Shark Nebula is a target I’ve always had in the back of my mind. An interstellar shark floating through space just has a really cool vibe to it.
But there’s a reason I hadn’t gone after this target until now, so let me explain. The Dark Shark is what astronomers call a dark nebula. It consists of cold interstellar dust, and unlike the colorful emission nebulae that emit their own light, this dust is only illuminated by the faint, scattered starlight of nearby stars. In short, it’s incredibly faint, much fainter than any other target I’ve imaged before.

And if that wasn’t challenging enough, dark nebulae are also broadband targets, meaning that light-pollution filters can’t be used to clean up the data. Such filters would block not only the skyglow but also the photons from the target itself.

Knowing all that, I still decided to use a few clear nights to give it a try, partly because I really wanted a challenge. I chose the Samyang 135mm lens again since it’s still my fastest piece of glass, and if that speed is ever needed, it’s for a target like this one. Even though I only got two clear nights instead of the three I had planned, I’m still very happy with the final result.