NGC 7331 ~ The Milky Way's Twin?
| Optics: |
RC Optical System 20" F/8.2 (4165.6 mm Focal Length) |
Date: |
June-August 2020 |
| Camera: |
SBIG STXL-11000 with AO-X Adaptive Optics |
Location: |
Columbus, Texas |
| Exposure: |
LRGB = 820:80:80:100 minutes |
Imager: |
Kent E. Biggs |
NGC 7331 is an
unbarred spiral galaxy about 40 million light years away in the
direction of the constellation Pegasus, the winged horse of
ancient Greek mythology. The words "in the direction of" is used
here, since no astronomical object is ever really "in" a
constellation. Constellations are made up collections of stars
by humans that are as fleeting as cloud shapes on an
astronomical scale. NGC 7331 appears to be surrounded by a group
of galaxies, but all of the other galaxies highlighted in this
image are much much further away at 300 and 400
million light years distant. Hovering over the image will show
the names of the other brighter galaxies in this image. Until
the early 2000s, it was believed that NGC 7331 was very
similar to our own Milky Way galaxy and hence called its twin.
However, discoveries have proven that our galaxy, although
similar in size and number of stars, is actually a barred spiral
galaxy that has a bar structure running through the center. NGC
7331 cleary has no bar and is therefore different from our own
galaxy. One interesting observation about NGC 7331 is that if
you look closely enough you will see that the center core of the
galaxy is not perfectly centered, as it favors the left side in
this image. Furthermore, it appears slightly inclined compared to the
disk of the entire galaxy. Amazing enough, this central disk is
actually rotating in the opposite direction of the galaxy, a
mystery among many others about the nature of galaxy formation
and their behaviors.
NGC 7331 - Earlier Imaging and Gen1 Processing.
| Optics: |
RC Optical System 20" F/8.2 (4165.6 mm Focal Length) |
Date: |
October 2010 |
| Camera: |
SBIG ST10XME with Adaptive Optics |
Location: |
Columbus, Texas |
| Exposure: |
LRGB = 400:120:80:120 minutes |
Imager: |
Kent E. Biggs |
NGC 7331 is one of
the most impressive spiral galaxies in the sky. It is the
brightest galaxy not to be included in the famous Messier
catalog of 100+ objects familiar to most amateurs. Some refer to
this galaxy as our own Milky Way Galaxy's twin due to its
appearance, but recent research suggests that our galaxy is
actually a barred spiral. NGC 7331 is often called the Deer Lick
Group named by Tomm Lorenzin coinciding with his best view of
the group during a trip to the Deer Lick Gap in the Smokey
Mountains. At 40-50 million light years, NGC 7331 is moving away
from us at over 500 miles per second and is slightly larger than
our own galaxy. The "smaller" galaxies in the image are far in
the distant and probably of similar size and mass to this
galaxy. The stats for this galaxy are RA: 22h 37m 04.5s, Dec:
+34° 25' 00", Mag: 9.4 (V), Size: 14.5'x3.7', Class: SA(s)b.