Explanation:
One of the brightest galaxies in planet Earth's sky and similar in size
to the Milky Way,
big, beautiful spiral M81
lies 11.8 million light-years away
in the northern constellation Ursa Major.
This remarkably deep image
of the region reveals details in the bright
yellow core, but at the
same time follows fainter features along the galaxy's gorgeous blue
spiral arms and
sweeping dust lanes.
Above M81 lies a dwarf companion galaxy,
Holmberg IX,
sporting a large,
pinkish star-forming
region near the top.
While M81
and Holmberg IX are seen through a foreground of stars in our
own Milky Way galaxy, they
are also seen here through a much fainter complex of dust clouds.
The relatively unexplored clouds
are likely only some hundreds of light-years distant and lie high
above our galaxy's plane.
Scattered through the image, especially at the the right, the dust
clouds reflect the combined light of the
Milky Way's stars and have been dubbed
integrated
flux nebulae.
