Explanation:
A cosmic bridge of stars, gas, and dust stretches
for over 75,000 light-years and joins this
peculiar
pair of galaxies
cataloged as Arp 87.
The bridge is strong evidence
that these two immense star systems have
passed close to each other
and experienced violent tides induced by
mutual
gravity.
As further evidence, the face-on spiral galaxy on
the right, also known as NGC 3808A,
exhibits many young blue star clusters produced in a burst
of star formation.
The twisted edge-on spiral on the left (NGC 3808B) seems to be wrapped
in the material bridging the galaxies and
surrounded by a curious
polar ring.
While such interactions are drawn out over billions of years, repeated
close
passages should ultimately result in
the merger of this pair of galaxies into a larger single
galaxy of stars.
Although
this
scenario does look peculiar, galactic mergers are thought
to be common, with Arp 87 representing a stage in
this
inevitable process.
The Arp 87 pair are
about 300 million light-years
distant toward the constellation Leo.
The prominent edge-on spiral at the far left
appears to be a more distant background galaxy and
not involved in the on-going merger.
