What is going on with this galaxy?
NGC 2685 is a confirmed polar ring galaxy - a rare
type of galaxy with
stars, gas and dust orbiting in rings perpendicular to the plane of
a flat galactic disk.
The
bizarre configuration could be
caused by the chance
capture of material
from another galaxy by a disk galaxy,
with the captured debris strung out in a rotating ring.
Still, observed
properties of NGC 2685
suggest that the rotating
helix structure is remarkably old and stable.
In this sharp view of the peculiar system also known as
Arp
336 or the Helix galaxy, the strange, perpendicular rings
are easy to trace as they pass in front of the galactic disk,
along with other
disturbed outer structures.
NGC 2685 is about 50,000
light-years
across and
40 million light-years away in the constellation of the Great Bear
(
Ursa Major).