Explanation:
This colorful cosmic skyscape
features a peculiar system
of galaxies cataloged as Arp 227 some 100 million light-years
distant.
Swimming
within
the boundaries of the
constellation Pisces,
Arp 227 consists of the two galaxies
prominent on the left;
the curious shell galaxy NGC 474 and its blue,
spiral-armed neighbor NGC 470.
The faint, wide arcs or
shells
of NGC 474 could have been formed by a
gravitational encounter with neighbor NGC 470.
Alternately the shells could be
caused by a merger with a
smaller galaxy producing an effect analogous to ripples across
the surface of a pond.
Remarkably, the large galaxy on the right hand side of the deep image,
NGC 467, appears to be surrounded by faint shells too,
evidence of another
interacting
galaxy system.
Intriguing background galaxies are scattered around
the field that also includes
spiky foreground stars.
Of course, those stars lie well within our own
Milky Way Galaxy.
The field of view spans 25 arc minutes or about 1/2 degree
on the sky.
Poll:
Which of last weeks APODs should be the APOW?
