At the heart of the Lagoon Nebula in Sagittarius lies the diminutive Hourglass Nebula. This extremely bright object is associated with the insignificant star alongside it, named Herschel 36 after its discoverer. Herschel described M8 as a noble nebula and a fine and complicated nebula, but he was clearly intrigued by the Hourglass which he compared to the nucleus of the Andromeda nebula, M31 as decidedly not stellar.

Surrounding the Hourglass is an extensive emission nebula, popularly known as the 'Lagoon' in allusion to the sinuous dark lane winding through it. The dusty division seems to separate the Hourglass nebula from a scattered open cluster, NGC 6530, at left of the picture here. It seems likely that the cluster is evidence of an earlier bout of star formation here, which has now spread westwards, into the Hourglass region. The cluster formed about 10 million years ago and is 5000 light years distant.

This AAT image was made from a plate taken in blue light.