Jan 31 2015
This NASA Hubble Space Telescope photo of NGC 7714 presents an especially striking view of the galaxy's smoke-ring-like structure. The golden loop is made of Sun-like stars that have been pulled deep into space, far from the galaxy's center. The galaxy is located approximately 100 million light-years from Earth in the direction of the constellation Pisces.
At first glance, galaxy NGC 7714 resembles a partial golden ring from an amusement park ride. This unusual structure is a river of Sun-like stars that has been pulled deep into space by the gravitational tug of a bypassing galaxy (not seen in this Hubble Space Telescope photo). Though the universe is full of such colliding galaxies that are distorted in a gravitational taffy-pull, NGC 7714 is particularly striking for the seeming fluidity of the stars along a vast arc. The near-collision between the galaxies happened at least 100 million years ago. Credit:Credit: NASA and ESA; Acknowledgment: A. Gal-Yam (Weizmann Institute of Science)
The universe is full of such galaxies that are gravitationally stretched and pulled and otherwise distorted in gravitational tug-o'-wars with bypassing galaxies.
The companion galaxy doing the "taffy pulling" in this case, NGC 7715, lies just out of the field of view in this image. A very faint bridge of stars extends to the unseen companion. The close encounter has compressed interstellar gas to trigger bursts of star formation seen in bright blue arcs extending around NGC 7714's center.
The gravitational disruption of NGC 7714 began between 100 million and 200 million years ago, at the epoch when dinosaurs ruled the Earth.
Source: http://www.spacetelescope.org/