NGC 7479 is
a classical barred spiral galaxy located in the direction of the
constellation Pegasus. It is also designated Caldwell 44, in the
Caldwell Catalogue of 109 objects. Patrick Moore created
this catalogue of clusters, nebulae, and galaxies to extend the
well known
Messier
Catalogue of objects which was intended to eliminate
mistaking objects as highly sought after new comets. There are
three interesting facts about the Caldwell catalogue. First, it
includes many objects bigger and brighter than the earlier
Messier list, since Messier really only cared about objects that
could be confused as comets. Second, Moore used his surname
Caldwell, since the first initial of Moore and Messier are the
same. He did not want two different “M1”s for instance. Third,
Moore did not actually discover any of the 109 objects in his
list, so its history and use leads to some controversy in
astronomy circles.
William Hershel, not Moore,
discovered NGC 7479 in 1784. It has intense starburst activity
from the nucleus, all the way to the outer arms. It has also
undergone a relatively recent merger with a smaller galaxy as is
evident by radio images of the galaxy showing arms expanding in
the opposite direction of the visible arms seen here. It is also
a recent source of 2 supernova in 1990 and 2009 where stars
ending their life exploded and briefly shined brighter than any
other star in the galaxy.
While there are many much
fainter galaxies in this image, NGC 7479 is somewhat unique in
that there are no other galaxies nearby. All faint galaxies
visible are much, much further away. It is as if NGC 7479 has
merged with everything close by already, therefore, it will, for
many billions of years, remain isolated on its own, untouched by
future mergers. The galaxy is about 105 million light years away
and about 150 thousand light years across.
In the image
above, inset and enlarged are three very distant galaxies, only
one identified in the million galaxy PGC catalog as PGC 1405069.
These distant galaxies are 100s of millions of light years away with the
light we see leaving dated to when earth was just starting more complex
life forms.
In the video below, several things are visible
and evident. First, note how the atmosphere changes throughout
as evident by the stars changing shape and size. Each frame is
10 minutes long of exposure but only 1/5 second long in the
video. Second, the bright lines streaking across the image are
either airplanes or satellites that continue to be a problem for
astronomers. These planes and satellites orbit earth. Third, in addition to the NGC 7479 galaxy, there
are two faint visible asteroids or space debris visible. The
first is just to the left of the galaxy and appears to be
leaving it; the second is more challenging to find. These asteroids are in our own
solar systems orbiting the sun or earth. The stars in the image
are outside our solar system but within our galaxy. All the
other faint smudges are distant galaxies outside our own Milky
Way Galaxy!
*Using a mouse, hover over the images
above for annotations, insets, and enlargements. The video below
can be paused and made full screen as well.