The first identified compact galaxy group, Stephan's Quintet is featured in this image.
The galaxies of the quintet are gathered near the center of the field, but really only four
of the five are locked in a cosmic dance of repeated close encounters taking place some 300
million light-years away. The odd man out is easy to spot, though. The interacting galaxies,
NGC 7319, 7318A, 7318B, and 7317 have a more dominant yellowish cast. They also tend to have
distorted loops and tails, grown under the influence of disruptive gravitational tides.
The mostly bluish galaxy, NGC 7320, is in the foreground about 40 million light-years distant,
and isn't part of the interacting group. Still, captured in this field above and to the right
of Stephan's Quintet is another galaxy, NGC 7320C, that is also 300 million light-years
distant. Of course, including it would bring the four interacting galaxies back up to
quintet status. Stephan's Quintet lies within the boundaries of the high flying constellation
[Text from APOD]