Here you can see LBN 681, located in the constellation Camelopardalis. Although it has no widely recognized popular name, astrophotographers sometimes refer to it as the "Cosmic Waterfall." Notice how the blue starlight appears to cascade through dark clouds of dust.
This "waterfall" does not emit its own light; it is a so-called reflection nebula. It works much like fog illuminated by car headlights — in this case, the "headlights" are hot stars. The nebula takes on its beautiful blue hue because interstellar dust scatters blue light more effectively, much like Earth's atmosphere makes our sky appear blue.
LBN 681 is extremely faint. Capturing these blue streams and dark dust requires many hours of exposure, especially when imaging under a light-polluted urban sky. The nebula is virtually invisible in individual 5-minute exposures and only gradually emerges when a large number of these frames are stacked together.
Gear used:
- Stellarvue SV102ED with William Optics 0.8x focal reducer (effective focal length 570 mm, f/5.6)
- Atik 428EX Color camera with Baader Planetarium UV/IR-cut filter
- QHY mini guide scope + QHY5L-II guide camera
- Celestron CG-5 mount with EQStar system
Acquisition details:
- 194 × 300-second exposures, binning 1x1, ~16 hours total
- Additionally, 94 × 180-second exposures were captured at 2×2 binning (~4.7 hours total) and incorporated into the synthetic luminance channel to improve its signal
- Sensor cooled to -10°C
If you looked at one of the raw frames, you probably wouldn't believe there was a nebula hiding in there. To be honest, it looks more like an ordinary star field than the beginning of a deep-sky image!
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