Some galaxies are all about the angle. NGC 5907, popularly known as the Splinter Galaxy (or the Knife Edge Galaxy), is a spiral galaxy seen almost perfectly edge-on, and the result is one of the most striking sights in the northern sky: an impossibly thin blade of light stretching across the field.
About the Galaxy
NGC 5907 (also catalogued as NGC 5906) lies roughly 46.5 million light years away in the constellation Draco. Because we view it nearly edge-on, its dust lanes and disk structure are silhouetted beautifully against the starlight, giving it that signature splinter appearance. Narrow, elongated galaxies like this are a fantastic challenge for astrophotographers: they reward long integration times that tease out the faint dust and halo light on either side of the disk.
Acquisition Details
- Integration: 39 x 180-second exposures, captured across two nights
- Capture software: N.I.N.A 3
- Processing: Stacked in Siril 1.4
- Telescope: Orion 8″ 1000mm f/4.9 Newtonian reflector
- Mount: Orion Atlas EQ-G
- Imaging camera: Canon T3i (full spectrum modified), at prime focus
- Guide scope: Meade 800mm f/10 reduced to f/5 with Atik 0.5x focal reducer (ADM rings)
- Guide camera: Meade DSI Pro monochrome 16-bit
Why Edge-On Galaxies Are So Photogenic
When a spiral galaxy’s disk aligns with our line of sight, its dust lanes cut dramatic dark lanes through the glow of billions of stars. NGC 5907 is a classic example of a relatively undisturbed edge-on, unlike the warped disk of NGC 4631, the Whale Galaxy, which I featured earlier this month. Comparing the two side by side is a great lesson in how a galaxy’s history shapes its structure.
If you want to try your own edge-on target, spring and early summer are prime galaxy season. Start with short exposures to find the thin disk, then build integration time to bring out the faint extensions. Check out my earlier tutorials on calibration frames and stacking in Siril for getting the most from your subframes.
See the full-resolution version in the gallery.
