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Old August 19th 09, 06:04 PM posted to alt.binaries.pictures.astro
Rick Johnson[_2_]
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Default Astro: UGC 12342 and UGC 12350

Guess you'll have to convince them to point Hubble at it. I checked
their data base and they haven't so far.

I'm trying to remember what drew my attention to this one. It was on my
todo list with a note that color would require more frames than normal
if UGC 12350 was in the frame. So I'd learned something about it
somewhere but couldn't track that down. I hate it when I leave myself
incomplete notes like that.

Rick

Richard Crisp wrote:
I just love these twisties

Wouldn't it be great to have amazing seeing and a huge scope so you could
really zoom in on these puppies?

"Rick Johnson" wrote in message
. com...
UGC 12342 (PGC 70414) and UGC 12350 are the two main galaxies in the
image. UGC 12342 is the seagull like galaxy and is about 355 million
light years away. It is classed as SB? I can't even tell if it is 1 or
2 galaxies. I see nothing indicating it is two but in the 2x
enlargement I can see hints that 2 may be involved. How else to explain
the messy state it's in. It was picked up by the 2 micron survey so
likely has massive star formation hidden behind dust, another indicator
of a collision in progress. UGC 12350 is only about 82 to 96 million
light years away (depending on who you listen to). So it is just
sharing the same field of view with UGC 12342. It is classed as Sm.

More interesting is the tiny pair of galaxies east of 12350. They are
2MASX J23053932+1650548 and have a red shift distance of 1.3 billion
light years. They appear to be an interacting pair. I can't find
anything on them however.

While there are a handful of other 2MASX galaxies in the image there is
little on them.

I took this one the night of August 17, 2009 (UT) and it is my most
recent image. This one would have been a difficult one to process the
color data using 10 minute subs. I knew this to be the case, that's why
I chose it for a test. Instead of my normal 2, 10 minute images for
color data in each channel I used 1 20 minute for each color. The
result was a very noticeable drop in noise level as only it contained
only one read noise set instead of two. It sure made processing the
color data easier and the colors a lot less noisy. UGC 12350's faint
disk would have been full of red and green speckles I'd have had to deal
with but they never even showed up. This greatly reduced my processing
time. It's likely I'll be using 20 minute sub frames for color in the
future. Still have to test that with the luminosity data however. I'm
not so sure it will be as much help in the luminosity data. For
instance focus accuracy is a minor issue in color data but major in
luminosity. I'm not sure my temperature compensation routines are
accurate enough for 20 minutes on nights of rapidly dropping
temperatures for instance. They aren't for 30 minute subs when using
Ha. I have to limit that to nights that don't have a rapid temperature
drop.

These galaxies are located in Pegasus just north of Markab the southwest
star of the Great Square of Pegasus and at the base of the horse's neck.

I've included a 2x enlargement of UGC 12342 better showing its very
weird detail.

14" LX200R @ f/10, L=4x10', RGB=1x20'x3, STL-11000XM, Paramount ME

Rick