Arp 81: 100 Million Years Later
From planet Earth, we view this strongly interacting
pair of galaxies,
cataloged as
Arp
81, as they were only about 100 million
years after their mutual closest approach.
The havoc wreaked
by gravity during their ominous encounter is
detailed in this color composite image from the Hubble Space Telescope,
showing twisted streams of gas and dust, a chaos of massive
star formation,
and a tidal tail
stretching for 200 thousand light-years or so as it
sweeps behind the cosmic wreckage.
Also known as NGC 6622 (left) and NGC 6621, the galaxies are
roughly equal in size but
are destined to merge
into one large galaxy in the
distant future,
making repeated approaches until they finally
coalesce.
Located in the constellation
Draco,
the galaxies are 280 million
light-years away.
The dark vertical band which seems to run through NGC 6621's location is
a camera artifact.