NGC 891: A Close-Up Look at the Silver Sliver Galaxy

NGC 891, also known as the Silver Sliver Galaxy, has long been a subject of fascination for astronomers. With its edge-on orientation and similarity to our own Milky Way, it presents a wealth of mysteries waiting to be unraveled.

In this article, we’ll take a close-up look at NGC 891 and answer some questions you may have about this enigmatic celestial body.

Where is NGC 891 located?

NGC 891 is a galaxy located in the constellation of Andromeda, about 27.3 ± 1.8 million light-years away from Earth. It is a member of the NGC 1023 group of galaxies in the Local Supercluster.

It is considered one of the closest and best analogs to the Milky Way, making it a valuable subject for studying galactic structure from an external perspective.

What type of galaxy is NGC 891?

NGC 891 is an edge-on unbarred spiral galaxy. This type of galaxy lacks a central bar like the one in our own Milky Way galaxy. However, some infrared observations suggest the presence of a weak central bar, making its classification as SBb possible.

How big is NGC 891?

Its disk is approximately 130,000 light-years (~40 kpc) in diameter and contains a prominent dust lane that runs along its midplane. The galaxy also has a prominent central bulge and a halo of stars that extends far beyond its disk.

Deep imaging has revealed a vast halo of gas, dust, and stars extending several thousand light-years above the galactic plane, likely driven by supernova explosions pushing material into the surrounding space.

Why is NGC 891 known as the Silver Sliver Galaxy?

This unique galaxy is often referred to as the Silver Sliver Galaxy due to its thin, elongated shape from our vantage point. It’s a popular target for astronomers due to its edge-on orientation, which gives us a rare opportunity to study its structure and contents.

For amateur astronomers, NGC 891 appears as a faint, cigar-shaped smudge in medium-sized backyard telescopes under dark skies, offering a rewarding challenge for deep-sky observers.

Why is NGC 891 also known as the Outer Limits Galaxy?

NGC 891 is sometimes called the Outer Limits Galaxy because it appeared in the end credits of the famous Outer Limits TV show alongside the Andromeda Galaxy, M67, the Sombrero Galaxy, the Pinwheel Galaxy, NGC 5128, NGC 1300, and M81. This TV show brought some recognition to this galaxy in popular culture.

Conclusion

Despite its relative proximity, there is still much we don’t know about NGC 891, and astronomers continue to study this fascinating galaxy to unravel its mysteries. It remains a benchmark galaxy for testing computer models of dust distribution, halo formation, and the dynamics of the interstellar medium. Its striking appearance and rich structure ensure it will remain a favorite target for both professional and amateur astronomers for years to come.