The Lagoon Nebula is an
emission nebula in the
constellation Sagittarius. It's also called M8,
in the
Messier catalog, or
NGC 6523.
As for many other nebulae, a cluster of stars
that have formed in the nebula's material was
discovered first. It is actually unknown if
Charles Messier ment to catalogue the
cluster or the nebula, but today M8 is used
for the nebula alone.
A remarkable feature of the Lagoon Nebula is the presence
of dark nebulae, known as "globules", which are in fact
collapsing protostellar clouds.
Another remarkable feature
is a very distinct shape that has been named
the "Hourglass Nebula",
which is a region where a vivid star formation
process seem to take place currently, and where
hot, young stars excite the surrounding gas causing it
to glow so brightly.
The nebula is quite bright, having a visual magnitude of 6.0,
making it an excellent target for amateur astronomers.