M16: Dust and an Open Cluster
Credit:
The photogenic
M16 shown above is composed of a
young star cluster and a
spectacular emission nebulae
lined with distinct regions of
interstellar dust.
Most of the stars in the
cluster
can be seen offset just above and to the right of the photograph's center.
This type of star cluster is called an "open" or "galactic" cluster and
typically has a few hundred young bright members. The redness of the
surrounding
emission nebula gas is caused by
electrons recombining with hydrogen nuclei, while the dark regions are
dust lanes that absorb much of
the radiation that enters it. The dust absorbs so much light it allows
astronomers to determine which stars are inside the nebula and which are in
the foreground.