ASTRO: NGC 3953 and UGC 06840

NGC 3953 and UGC 06840 a pair of galaxies with the same redshift putting
them about 55 to 60 million light-years distant. They are located in
Ursa Major about 1 1/3 degrees south of Phecda, the southeastern star in
the bowl of the "Big Dipper". NGC 3953 is a beautiful multi-armed,
somewhat flocculent barred spiral with a very odd arm structure on the
eastern (left) side. Two arms seem to suddenly join and end in a bunch
of star clusters. The Sloan image shows the star-like object at the tip
as very green. Still I think it really is a star. Sloan's multiband
color filter system can create green stars. I thought this odd arm
system might have attracted Arp's attention but apparently not. UGC
06840 in the southwest corner of my image has almost exactly the same
redshift but is a very different galaxy. It has a very low surface
brightness except for the bar that causes it to be classed as a barred
spiral of the Magellanic type. The two galaxies make for a nice contrast.

There's another low surface brightness galaxy about half way between
them, at least as seen from our galaxy. It is MCG +09-20-023.
Unfortunately I can't find any redshift data for it so I have no idea if
it could be related to the first two.

Also in the annotated image are a couple objects identified as being
both a quasar and a galaxy. They must show a quasar like spectrum but
certainly are faint for a typical quasar. Normally they are so bright
they hide any hint of the galaxy the reside in. These two are dim
enough some of the galaxy is visible though my seeing makes that hard to
see.

There seems to be a family of galaxies at about 1.1 billion light-years
centered on the lower left part of my image. I found no cluster listed
for that location though I looked only about 15 minutes beyond the
3953image edge.

As "usual" conditions were poor for this image, especially seeing. Some
frames had seeing of 2.75" while others were over 6 though the luminance
frames used were no worse than 4". The highly varied seeing caused
havoc with color. Some stars in a frame were far worse than others.
This created some color flares around stars that might be blue for one
and red for another. I did a lot of local deconvolution trying to get
the stars to similar sizes but finally gave up. It will be easier to
reshoot this one next year. Due to the poorer than normal seeing for
the luminance as well I lost a lot of detail that I'd hoped to capture.
There's some interesting fine dust detail near the core of NGC 3953
that shows in the best luminance frame but is lost in the other three I
used. I took some 25 frames and used the "best" 10 though calling some
of them "best" is rather stretching things beyond reason.

This one reminds me of a buzz saw blade slicing through space.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick


--
Prefix is correct. Domain is arvig dot net

I think your registration might be a bit off. There are red halos
on top of every star, and blue halos below. It's pretty consistent
across the entire image. There's even a thin band of 'red' across
the entire top of the frame for about a half dozen pixels.

Beautiful work just the same.

Brian
--
http://www.earthwaves.org/wwwboard/wwwboard.html - Earthquake prediction &
Earth Sciences
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Sed quis custodiet ipsos Custodes?

Mighty image Rick. I have imaged NGC 3953 but were not aware of the other
"large" galaxy in it's vicinity.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

NGC 3953 and UGC 06840 a pair of galaxies with the same redshift putting
them about 55 to 60 million light-years distant. They are located in
Ursa Major about 1 1/3 degrees south of Phecda, the southeastern star in
the bowl of the "Big Dipper". NGC 3953 is a beautiful multi-armed,
somewhat flocculent barred spiral with a very odd arm structure on the
eastern (left) side. Two arms seem to suddenly join and end in a bunch
of star clusters. The Sloan image shows the star-like object at the tip
as very green. Still I think it really is a star. Sloan's multiband
color filter system can create green stars. I thought this odd arm
system might have attracted Arp's attention but apparently not. UGC
06840 in the southwest corner of my image has almost exactly the same
redshift but is a very different galaxy. It has a very low surface
brightness except for the bar that causes it to be classed as a barred
spiral of the Magellanic type. The two galaxies make for a nice contrast.

There's another low surface brightness galaxy about half way between
them, at least as seen from our galaxy. It is MCG +09-20-023.
Unfortunately I can't find any redshift data for it so I have no idea if
it could be related to the first two.

Also in the annotated image are a couple objects identified as being
both a quasar and a galaxy. They must show a quasar like spectrum but
certainly are faint for a typical quasar. Normally they are so bright
they hide any hint of the galaxy the reside in. These two are dim
enough some of the galaxy is visible though my seeing makes that hard to
see.

There seems to be a family of galaxies at about 1.1 billion light-years
centered on the lower left part of my image. I found no cluster listed
for that location though I looked only about 15 minutes beyond the
3953image edge.

As "usual" conditions were poor for this image, especially seeing. Some
frames had seeing of 2.75" while others were over 6 though the luminance
frames used were no worse than 4". The highly varied seeing caused
havoc with color. Some stars in a frame were far worse than others.
This created some color flares around stars that might be blue for one
and red for another. I did a lot of local deconvolution trying to get
the stars to similar sizes but finally gave up. It will be easier to
reshoot this one next year. Due to the poorer than normal seeing for
the luminance as well I lost a lot of detail that I'd hoped to capture.
There's some interesting fine dust detail near the core of NGC 3953
that shows in the best luminance frame but is lost in the other three I
used. I took some 25 frames and used the "best" 10 though calling some
of them "best" is rather stretching things beyond reason.

This one reminds me of a buzz saw blade slicing through space.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick


--
Prefix is correct. Domain is arvig dot net