NGC 5907 (Draco)

The edge-on spiral galaxy NGC 5907 (Splinter Galaxy, Caldwell 17, occasionally also listed as NGC 5906 due to a historical cataloguing ambiguity) in the constellation Draco is one of the finest examples of a spiral galaxy viewed almost exactly from the side. Its remarkably thin, elongated profile gives it the appearance of a glowing splinter of light suspended in space, earning it the popular nickname “Splinter Galaxy.” A prominent dust lane runs through the galactic disk, while the spiral arms are largely hidden by its nearly edge-on orientation.

NGC 5907 lies at a distance of approximately 50 million light-years from Earth and has an estimated diameter of about 170,000 light-years, making it significantly larger than the Milky Way. Despite its impressive size, the galaxy remained little known for many years because its orientation conceals much of its spiral structure. Infrared observations reveal a substantial stellar disk and confirm its classification as a spiral galaxy.

One of the most fascinating features of NGC 5907 is its extensive stellar tidal stream, a faint system of loops and arcs surrounding the galaxy (not visible in my image). These structures are believed to be the remnants of a dwarf galaxy that was gradually torn apart by NGC 5907’s gravity over billions of years. The discovery of this tidal debris provided striking evidence that large galaxies continue to grow through the accretion of smaller companions.

NGC 5907 was discovered in 1788 by the German-British astronomer William Herschel.

Technical Details:
Exposure time: 3h 39min (73x3min)
Gain: 100
Temperature: -10°C
Date: April 17/18, 2026
Processing: Astro Pixel Processor (APP) and Photoshop
Calibration: Darks, flats, and bias

Equipment:
Cooled ASI 2600MC Pro camera, TeleVue Paracorr Type II coma corrector, 8" f/5 "ONTC" Newtonian telescope, ZWO AM5 Strain Wave Mount, ZWO OAG-L off-axis system, ASI 174MM Mini guide camera, ASIAIR Plus