Pictures of edge-on galaxy NGC 891

Not all galaxies appear to us on Earth as face-on spiral structures: some are angled edge-on from our perspective, like the Needle Galaxy, for example, or galaxy NGC 3628 in the Leo Triplet.

Edge-on galaxy NGC 891 is 30 million lightyears away in the Andromeda constellation, and spans about 100,000 lightyears across.

NGC 891 is also known as Caldwell 23: part of the deep-sky Caldwell Catalogue compiled by Sir Patrick Moore, who famously said the galaxy looks like "two fried eggs clapped back to back".

Observations of NGC 891 with the Hubble Space Telescope have revealed that the galaxy’s galactic halo - a sphere of thinly-dispersed stars and other cosmic material surrounding the galaxy - mostly contains ancient stars, many of which are found grouped in some of the most ancient objects in the Universe: globular clusters.

Hubble data also suggests that the halo is comprised of material similar in composition to other material in NGC 891, which could mean it has been expelled from the main galaxy and is expanding outwards into space.

The expulsion of this cosmic material may be caused by intense star birth or the explosion of ageing stars in events known as supernovae.

NGC 891 is a spiral galaxy, and while we may never get to appreciate its spiral structure face-on, its edge-on tilt relative to Earth gives astronomers an amazing view of the dark lane of cosmic dust and gas running through the galactic centre.

Below is a selection of pictures of edge-on galaxy NGC 891 captured by astrophotographers and BBC Sky at Night Magazine readers from around the world.

For more info on astrophotography, read our astrophotography guides or discover how to fine-tune your astro images with our tutorial on image processing.

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