Explanation:
Spiral galaxy
NGC 7331
is often touted as an analog to our own
Milky Way.
About 50 million light-years distant in the northern constellation
Pegasus,
NGC 7331 was recognized early on as
a spiral
nebula and is actually one of the
brighter galaxies
not included in Charles Messier's famous 18th
century catalog.
Since the galaxy's disk
is inclined to our line-of-sight, deep telescopic
exposures often result in an image that evokes a strong
sense of depth.
The effect is further enhanced in this well-framed view by the
galaxies that lie beyond this beautiful
island universe.
The background galaxies are about one tenth the
apparent size
of NGC 7331 and so lie roughly ten times farther away.
