Bernard, I like this image. It looks like a "regular" spiral galaxy with
the bars only in the innermost section. Interesting that the very center of
the galaxy is an extremely bright white spot. One of the cool things about
this image is that the galaxy arms are very distinct all the way to their
ends. The dust and gas is well defined also, especially on the outer edge
of the galaxy. M109 looks like a tight precise object.
The stars throughout the image are nice and round even on the very edges and
corners. I can quickly count six other galaxies of various sizes in the
background and there is a nice spread of stars around M109 giving the image
good balance. This image does seem a little more noisy than your other
images, but that might be that the posted version is only 792 pixels on a
side. The full size version at 4096 x 4096 is better, but again not as
sharp as some of your recent pictures like M92 and M101. Maybe it is due to
the fact that M109 is 60 million light years away, my eyes are going, or I
have a crappy monitor on my laptop.
If I read your shoot data correctly this is 25 stacked 20 minute L
exposures, 12 15 minute exposures for R & G, and 11 15 minute B exposures.
Sometime I would like to understand your approach on how you chose those
number of exposures and the length of those exposures to stack into the
final image. It seems that most of the galaxy images in your gallery have
the same number and duration of exposures - even the Deer Lick Group.
Short version -it is a beautiful image of a very distant, difficult object.
Great job - as always for your work and thanks for letting us enjoy them.
Keep them coming...
Rob
-----Original Message-----
From: az-observing-bounce@xxxxxxxxxxxxx <az-observing-bounce@xxxxxxxxxxxxx>
On Behalf Of Bernard Miller
Sent: Tuesday, June 5, 2018 7:50 PM
To: az-observing@xxxxxxxxxxxxx
Subject: [AZ-Observing] M109
Hi,
This is an image of M109 (also known as NGC 3992). It is a barred spiral
galaxy about 60 million light years away in the constellation Ursa Major
Comments and suggestions appreciated.
http://www.azstarman.net/CDK/M109.htm
Thanks,
Bernard
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