Lagoon Nebula (M8)
The Lagoon Nebula (M8, NGC 6523) is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and as a H II region. In the foreground is the open star cluster NGC 6530.
The Lagoon Nebula is estimated to be between 4,000-6,000 light years from the Earth and measures 110 by 50 light years.
The nebula contains a number of Bok globules (dark, collapsing clouds of protostellar material). It also includes a funnel-like or tornado-like structure caused by a hot O-type star that emanates ultraviolet light, heating and ionizing gases on the surface of the nebula.
The Lagoon Nebula also contains at its centre a structure known as the Hourglass Nebula (the densest, brightest part). In 2006 the first four Herbig–Haro objects were detected within the Hourglass (a Herbig-Haro object is where jets emitted from a newly forming star interact with surrounding nebulosity).
This image was shot in mapped colour - Sulphur II emissions mapped to red, Hydrogen alpha to green and Oxygen III to blue - the so-called Hubble Palette.