Society for Popular Astronomy

Nebulae, clusters and galaxies

As well as stars and planets, you can observe some of the brighter galaxies, star clusters and nebulae in the night sky. They are the targets for our Deep Sky Section.

A nebula is basically a cloud of gas and dust within our own galaxy, which we call the Milky Way due to its appearance as a bright band when seen from within. A star cluster is, predictably, a collection of stars.

Vastly bigger collections of stars are galaxies, far beyond the Milky Way, which appear as fuzzy blurs in the night sky. You will need binoculars or a telescope to see all but the very closest and brightest.

A very detailed image of the ”Triffid” emission nebula, M20, by David Davies, from Cambridge.

So although nebulae and galaxies are quite different astronomical objects, they are similar in that both look like fuzzy blobs to the casual stargazer.

Indeed, a century or more ago, the difference between the two objects was not generally recognised by professional astronomers. There was a great debate before it was accepted that many blobs were other cities of stars outside our own Milky Way.

Seeking out and observing these heavenly blurs, whether galaxies, clusters or nebulae, can be a fascinating challenge when you are taking up stargazing. Inded many amateur astronomers spend their lives studying what they call deep sky objects.

Join the SPA and you will get expert guidance in how to observe the deep sky, whether you have a telescope or simply binoculars.

Click to visit the Deep Sky Section