NGC 5906 – The Splinter Galaxy
Key Scientific Data
Object type: Edge-on spiral galaxy – SA(s)c
Constellation: Draco
Other designations: NGC 5907, UGC 9801, PGC 54470, Caldwell 50, Splinter Galaxy, Knife Edge Galaxy
Distance from Earth: approximately 50–55 million light-years
Diameter: approximately 120,000 light-years
Apparent size: approximately 12.8 × 1.4 arcminutes
Apparent magnitude: approximately 10.3
Inclination: approximately 87°
Right Ascension: 15h 15m 53s
Declination: +56° 19′
Discovered by: William Herschel, 1788
Light-travel time: approximately 50–55 million years
Description
NGC 5906, more commonly known as NGC 5907, is a spectacular spiral galaxy in the constellation Draco, approximately 50–55 million light-years from Earth.
Viewed almost perfectly edge-on, its stellar disc appears as an exceptionally thin band of light, earning it the nicknames “Splinter Galaxy” and “Knife Edge Galaxy.”
Spanning approximately 120,000 light-years, it is comparable in size to the Milky Way. Its orientation conceals most of its spiral structure while revealing a narrow dust lane that partially obscures the stars behind it.
This unusual perspective makes NGC 5906 particularly valuable for studying the structure and distribution of stars, gas and dust within spiral galaxies.
NGC 5906 or NGC 5907?
The galaxy has an unusual double designation, originating from historical observations and the compilation of the New General Catalogue.
Early astronomers recorded what appeared to be separate objects, later recognised as parts of the same galaxy.
Today, NGC 5907 is the widely accepted designation, although NGC 5906 remains present in historical references and astronomical catalogues.
A Remarkably Thin Galaxy
NGC 5906 is distinguished by its extraordinarily thin stellar disc and relatively modest central bulge.
Most of its visible light is concentrated in a narrow, elongated structure rather than a prominent central region.
Its appearance offers astronomers an excellent opportunity to investigate the vertical distribution of stars and interstellar material, helping reveal how spiral galaxies are structured and evolve.
Curiosities
Discovered by William Herschel in 1788, NGC 5906 is among the most distinctive edge-on galaxies visible from Earth.
While ordinary photographs reveal a narrow streak of light, exceptionally deep observations have reported faint stellar streams and loops surrounding the galaxy.
These structures may be remnants of smaller satellite galaxies disrupted by gravitational interactions, providing evidence of ancient galactic mergers.
A Galactic Fossil Record
The faint structures surrounding NGC 5906 represent a possible fossil record of its evolutionary history.
When smaller galaxies approach larger ones, tidal forces can strip away their stars, stretching them into enormous streams that may survive for billions of years.
Detecting these extremely faint features requires exceptionally deep imaging.
Their study helps astronomers understand galactic mergers, tidal interactions and hierarchical galaxy formation — processes that have also shaped our Milky Way.
Looking Back in Time
The light captured from NGC 5906 (NGC 5907) began its journey approximately 50 million years ago, during Earth's Eocene epoch.
At that time, Earth was considerably warmer than today, tropical forests extended into higher latitudes, and early mammals, including ancestors of horses, whales and primates, were evolving.
Humans had not yet appeared, and the earliest hominins would not emerge for another 40 million years or more.
Throughout this immense period of terrestrial evolution, the photons recorded in this photograph were travelling across intergalactic space towards Earth.
Image Data
Total integration time: 17h 30m
Integration by filter:
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Luminance/Clear: 4h 45m (57 × 300")
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Red: 5h 15m (63 × 300")
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Green: 3h 45m (45 × 300")
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Blue: 3h 45m (45 × 300")
Equipment:
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Telescope: Artesky ARTEC 250 Pro
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Camera: Player One Poseidon-M Pro
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Mount: 10Micron GM2000 HPS II
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Filters: Antlia V-Pro LRGB 2"
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Accessories: Pegasus Astro Prodigy Microfocuser, Player One Phoenix Wheel 7×2", WandererAstro WandererCover V4-EC
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Software: Adobe Photoshop, Pleiades Astrophoto PixInsight, Stefan Berg Nighttime Imaging 'N' Astronomy (N.I.N.A. / NINA)
For further details and the full-resolution image, visit AstroBin: