Messier 8, the Lagoon Nebula, is one of the showpiece nebulae of the summer sky. It’s in Sagittarius so it is low in the south for those of us at mid-northern latitudes. But, it is worth pointing the telescope that low!

I’ve read that the Lagoon is actually bright and large enough to be seen with the naked eye if the sky is dark enough. I’ve never seen that myself but it’s believable. The nebula is twice as wide as the full moon and just a bit taller than the full moon so it is certainly big enough for the eye to resolve. The only question is if it is bright enough both in an absolute sense and relative to whatever sky glow you have. It’s easily visible in binoculars though the darker the sky, the easier it is to see.

This is an emission nebula. The ultraviolet light from young, hot stars is causing the gas to glow. There are many bok globules (those dark areas) where protostars are forming and will eventually light up as new stars.

According to Wikipedia, the nebula is 4,000 to 6,000 light years away and it spans about 110 x 50 light years.

The Lagoon Nebula is listed in many different catalogs as Messier 8, NGC 6523, Sh2-25, RCW 146 and Gum 72. It also contains the open cluster NGC 6530, and several of the Bok globules are listed in Barnard’s catalog of dark nebulae: B88, B89 and B296. It’s a very busy region!

This is only 10h 30m of SHO data. The region is so bright that additional time wasn’t needed. You can find all the technical details at astrobin.