NGC 2685
has been called the Helix Galaxy due to its uniquely and
intriguing, tightly wound corkscrew appearance. The galaxy lies
in the direction of the constellation
Ursa Major,
Latin for the “greater bear” or commonly known as the Big
Bear, the body of which is the Big Dipper. This galaxy is over
40 million light years away. At 50 thousand light years across
it is roughly half the size of our own
Milky Way
Galaxy.
NGC 2685 is a great example of a
polar-ring galaxy in that its ring rotates around the galaxy
over its pole. It was one of the earliest galaxies classified as
polar-ring. The cigar shaped yellowish center of the galaxy is
likely a flat disk with its poles perpendicular to it. Visible
here is the star and dust lanes of a likely merged galaxy
rotating in a ring formation over those pole, hence the
polar-ring name.
NGC 2685 is also an example of a
Seyfert
Galaxy. Seyferts have very active nuclei similar to
quasars. A
distinct difference from quasars, however, is that Seferts have
detectable surrounding host galaxies, whereas quasars do not.
Quasars are so distant and so active that their cores tend to
outshine any surrounding stars and other material making up the
host galaxy. Perhaps quasars are very early and lonely
supermassive black holes ingesting any material around them. One
of the studies the
James Webb Telescope hopes to achieve is to better understand
quasars and other galaxies with very active cores.
Visible also in this image (upper right) is two near edge-on
spiral galaxies, PGC 25034 and PGC 25046*. Visual just below NGC
2685 is another near face-on spiral galaxy without a
designation. All of these galaxies are likely much further
distant. Note to the upper right of NGC 2685 is a small galaxy
without much form; it is likely a dwarf satellite galaxy formed
from material left over from the ring galaxy’s merger with the
other galaxy forming the ring*. These insets are shown with the
stars removed.
In the first of three images below shows a zoomed-in version of the
latest processing (Gen 3). Hover over the image with a mouse shows
the earlier Gen 2 processing. The second image below shows the latest
image processing without stars. Hover over the image to replace the stars.
The third and final image below shows Gen 1
processing compared to Gen 3 when hovered over.
*Using a mouse, hover over the images above and below for annotations.
This hover feature may be unavailable on smart phones.
NGC 2685 Zoomed-In. Gen3 and Compared to Gen2 Process Workflow
