Accelerate to ramming speed! -- Arp 294

Arp 294 is an interacting pair of galaxies about 135 million light-years
distant in southern Ursa Major. It appears the upper one is about to
ram into the lower though this isn't likely the case at all. The image
did remind me of a much criticized line in the B5 series when a
spaceship Captain ordered "ramming speed". Arp classified them under
Group Character: Long filaments. I'd have classed it under Wind Effects
but it isn't my catalog. While the northern galaxy, NGC 3788, does have
a long filament that is typical of tidal interaction, the lower galaxy,
NGC 3786, has two rather unusual filaments that look a bit "wind blown".
They are likely tidally created however. Arp did see these as his
comment on the pair is simply; "Peculiar filaments." NGC 3786 is
classified as (R')SAB(r)a pec and has an active nucleus that appears to
be a Seyfert 1. NGC 3788 is classed as SAB(rs)ab pec. Both shine at
13th magnitude so should be visible in an 8" scope under dark skies.
The filaments however may challenge even the largest scopes.

The small galaxy just below NGC 3786 is SDSS J113939.20+315320.4 at 460
million light-years. The red vertical spindle galaxy east of NGC 3788 is
SDSS J114002.67+315607.1 is about 780 million light-years distant.

The spiral galaxy about 5 minutes of arc south west of Arp 294 is CGCG
157-007 about 400 million light-years away. It appears rather distorted
with tidal debris. This interaction must have happened some time ago as
there are no obvious nearby candidates for a partner. The "small"
galaxy to its west is SDSS J113918.50+315121 at 1 billion light-years.
Far too distant to be involved. Further west of it is the even
"smaller" galaxy SDSS J113912.92+315120.5 at 1.6 billion light-years.

The galaxies and quasars I was able to find red shift data on at NED are
shown on the annotated image. The most distant galaxy is 5.3 billion
light-years distant shining at fainter than 21st magnitude so at about
my limit on this image. Quasars range from just 2.9 to 12 billion
light-years.

SDSS image:
http://astronomerica.awardspace.com/.../NGC3786-8.php

The SDSS page makes reference to NGC 3793 as being CGCG 157-007. This
is wrong. NGC 3793 is a single star east, not west of Arp 294.
To find it on the SDSS image go from NGC 3786 to the bright red star
then continue almost of the same line about the same distance to this
rather bright star. It is directly below the vertical spindle of SDSS
J114002.67+315607.1 mentioned above. NGC 3797 is also a star in my
image but just out of the frame of the SDSS image. For a more complete
discussion of this mix-up see the NGC project entry for NGC 3793.
http://www.ngcicproject.org/dss/dss_n3700.asp I can't explain why the
very red star in the Sloan image is white with a blue halo in my shot.
SDSS uses three IR filters along with three visual band filters and it
could be those colors are so strong they skew the color to red. Very
bright stars cause blue halos in my filters but the star in question is
spectral class G0 so a pretty white star in reality. It is GSC
2523:1968/HIP 56900 for those who want to look it up.

This is my last April image (29th UTC). Moving to May. May was mostly
cloudy so only 3 images taken in May, all Arp galaxies.

Arp's image:
http://nedwww.ipac.caltech.edu/level...ig_arp294.jpeg

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

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

very nice shot.

"Rick Johnson" wrote in message
. com...
Arp 294 is an interacting pair of galaxies about 135 million light-years
distant in southern Ursa Major. It appears the upper one is about to
ram into the lower though this isn't likely the case at all. The image
did remind me of a much criticized line in the B5 series when a
spaceship Captain ordered "ramming speed". Arp classified them under
Group Character: Long filaments. I'd have classed it under Wind Effects
but it isn't my catalog. While the northern galaxy, NGC 3788, does have
a long filament that is typical of tidal interaction, the lower galaxy,
NGC 3786, has two rather unusual filaments that look a bit "wind blown".
They are likely tidally created however. Arp did see these as his
comment on the pair is simply; "Peculiar filaments." NGC 3786 is
classified as (R')SAB(r)a pec and has an active nucleus that appears to
be a Seyfert 1. NGC 3788 is classed as SAB(rs)ab pec. Both shine at
13th magnitude so should be visible in an 8" scope under dark skies.
The filaments however may challenge even the largest scopes.

The small galaxy just below NGC 3786 is SDSS J113939.20+315320.4 at 460
million light-years. The red vertical spindle galaxy east of NGC 3788 is
SDSS J114002.67+315607.1 is about 780 million light-years distant.

The spiral galaxy about 5 minutes of arc south west of Arp 294 is CGCG
157-007 about 400 million light-years away. It appears rather distorted
with tidal debris. This interaction must have happened some time ago as
there are no obvious nearby candidates for a partner. The "small"
galaxy to its west is SDSS J113918.50+315121 at 1 billion light-years.
Far too distant to be involved. Further west of it is the even
"smaller" galaxy SDSS J113912.92+315120.5 at 1.6 billion light-years.

The galaxies and quasars I was able to find red shift data on at NED are
shown on the annotated image. The most distant galaxy is 5.3 billion
light-years distant shining at fainter than 21st magnitude so at about
my limit on this image. Quasars range from just 2.9 to 12 billion
light-years.

SDSS image:
http://astronomerica.awardspace.com/.../NGC3786-8.php

The SDSS page makes reference to NGC 3793 as being CGCG 157-007. This
is wrong. NGC 3793 is a single star east, not west of Arp 294.
To find it on the SDSS image go from NGC 3786 to the bright red star
then continue almost of the same line about the same distance to this
rather bright star. It is directly below the vertical spindle of SDSS
J114002.67+315607.1 mentioned above. NGC 3797 is also a star in my
image but just out of the frame of the SDSS image. For a more complete
discussion of this mix-up see the NGC project entry for NGC 3793.
http://www.ngcicproject.org/dss/dss_n3700.asp I can't explain why the
very red star in the Sloan image is white with a blue halo in my shot.
SDSS uses three IR filters along with three visual band filters and it
could be those colors are so strong they skew the color to red. Very
bright stars cause blue halos in my filters but the star in question is
spectral class G0 so a pretty white star in reality. It is GSC
2523:1968/HIP 56900 for those who want to look it up.

This is my last April image (29th UTC). Moving to May. May was mostly
cloudy so only 3 images taken in May, all Arp galaxies.

Arp's image:
http://nedwww.ipac.caltech.edu/level...ig_arp294.jpeg

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

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

This is a fine image Rick, neat pair indeed. Wish I could see those
faint filaments a bit better though, you should be less chintzy on the L ;-)

Clear skies!

P.S. All my Mars stuff has been a wash so far; poor seeing or no seeing

Rick Johnson wrote:
Arp 294 is an interacting pair of galaxies about 135 million light-years
distant in southern Ursa Major.

SNIP


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

Rick


--
Adriano
http://www.edmar-co.com/adriano/

Here is is mostly no photons. Right now there's 18" of snow on the
roof. I need to get that off before I can even roll it. At -14F right
now I don't see that happening. Normally the Polaris tree greatly
limits snowfall on the roof but this year all our storms have come from
the south. Never seen that in the years we've lived here. First year
temps ever got above freezing this month. The garage with my truck
faces south so when we hit 34F the water all flowed against the door.
It is sealed by 4" of solid ice. I'll need a jack hammer to get that
door open before March. Hope I don't need the truck. Probably have
lots of ice in the roof track as well. Until I get that snow off I
won't know. Rolling the roof can cause it to suddenly avalanche into
the observatory. Did that the first winter. No fun shoveling all that
snow over a 6 foot wall!

As for more time I've found it of very little help. Even tripling the
time does little to increase depth. Noise level improves a lot so the
image is far less grainy but faint stuff just doesn't seem to show any
better, just a lot easier to process it. With so many targets and so
little scope time due to weather I've chose to put the time into the
processing end. I suppose if I would quadruple the time I might see
some gain but from the only slight improvement doubling gave I just
don't see it happening. What I really need is better transparency. On
an average night I reach about 22.5 mag objects but on a good night I
can go past 24! That's one heck of a difference. Far more than I'd
expect. Yet that's what the measurements show. Seeing helps a bit but
I'm talking galaxies with a size at least that of the seeing not point
sources. Get one of those nights and then I will consider more time as
then it does make a difference. Unfortunately they are rare.

Rick

Adriano wrote:
This is a fine image Rick, neat pair indeed. Wish I could see those
faint filaments a bit better though, you should be less chintzy on the L
;-)

Clear skies!

P.S. All my Mars stuff has been a wash so far; poor seeing or no seeing

Rick Johnson wrote:
Arp 294 is an interacting pair of galaxies about 135 million
light-years distant in southern Ursa Major.

SNIP


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

Rick




--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Well, it sure sounds like you have quite a few more more hurdles to
overcome than I do so I won't complain. Would still be nice to get ONE
decent image of mars this apparition though. Anywhoo... I didn't realise
you had transparancy issues, your images come out pretty good. Your
prolific contribution to the group is appreciated!

I've got the scope out waiting to see how Mars looks tonight. A little
steadyness is all I need!

Cheers,

Rick Johnson wrote:
Here is is mostly no photons. Right now there's 18" of snow on the
roof. I need to get that off before I can even roll it. At -14F right
now I don't see that happening. Normally the Polaris tree greatly
limits snowfall on the roof but this year all our storms have come from
the south. Never seen that in the years we've lived here. First year
temps ever got above freezing this month. The garage with my truck
faces south so when we hit 34F the water all flowed against the door. It
is sealed by 4" of solid ice. I'll need a jack hammer to get that door
open before March. Hope I don't need the truck. Probably have lots of
ice in the roof track as well. Until I get that snow off I won't know.
Rolling the roof can cause it to suddenly avalanche into the
observatory. Did that the first winter. No fun shoveling all that snow
over a 6 foot wall!

As for more time I've found it of very little help. Even tripling the
time does little to increase depth. Noise level improves a lot so the
image is far less grainy but faint stuff just doesn't seem to show any
better, just a lot easier to process it. With so many targets and so
little scope time due to weather I've chose to put the time into the
processing end. I suppose if I would quadruple the time I might see
some gain but from the only slight improvement doubling gave I just
don't see it happening. What I really need is better transparency. On
an average night I reach about 22.5 mag objects but on a good night I
can go past 24! That's one heck of a difference. Far more than I'd
expect. Yet that's what the measurements show. Seeing helps a bit but
I'm talking galaxies with a size at least that of the seeing not point
sources. Get one of those nights and then I will consider more time as
then it does make a difference. Unfortunately they are rare.

Rick

Adriano wrote:

This is a fine image Rick, neat pair indeed. Wish I could see those
faint filaments a bit better though, you should be less chintzy on the
L ;-)

Clear skies!

P.S. All my Mars stuff has been a wash so far; poor seeing or no
seeing

Rick Johnson wrote:

Arp 294 is an interacting pair of galaxies about 135 million
light-years distant in southern Ursa Major.


SNIP


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

Rick






--
Adriano
http://www.edmar-co.com/adriano/

34°14'11.7"N

I have no idea why some nights allow me to go really deep and the next I
can't. I see it in the first frame in. I don't see it looking at the
sky. Limiting visual magnitude to my aged eye is about 6.5 at the
zenith a typical night or one of better transpaency. I do see a drop in
ADU count from about 200 typical background to about 175. Those 25
counts are the only difference I see. My cloud sensor gives no
indication that I can read. Clear Sky Clock's transparency prediction
seems useless. Seeing it often hits on but I can't see anything but
random hits on transparency.

Living on a lake I have lots of water vapor to contend with. That is
the only variable I can think of that is hitting me. In winter it forms
ice crystals that really increase my background ADU to 800 but that has
little effect on how deep I go but does decrease S/N. Some images will
use 5 or 6 subs. That usually means my background ADU jumped due to fog
or ice in the air. Again, I don't see it visually at all. I keep
thinking I should get a meter to measure this but for the few
measurements even the $150 or so they cost seems steep so I never open
the wallet.

I just take that first frame of the night, See what the background ADU
is (after calibration) and take my luminosity images or the night
accordingly.

Now if you want to come up and pull all that snow off my roof (I've done
it once this year at -20F) be my guest. Its "interesting" being atop a
10 foot ladder on a deck 8' above ground level right along the railing
reaching over that railing with a 22' snow rake pulling hundreds of
pounds of snow off the roof without tipping the ladder or me over that
railing. At least there's a couple feet of snow to break my fall. I've
come close a couple of times but so far so good. 50 years ago I'd have
thought nothing of doing this. Each year it gets a bit more
"interesting" with my wife's finger above the 911 buttons on the phone.
while she's holding the laddar so she can go over the railing with me if
I pull too hard and the snow doesn't give.

Hope the atmosphere will steady down for you. I've not even looked
visually at Mars this year. Just too cold.

Rick


Adriano wrote:
Well, it sure sounds like you have quite a few more more hurdles to
overcome than I do so I won't complain. Would still be nice to get ONE
decent image of mars this apparition though. Anywhoo... I didn't realise
you had transparancy issues, your images come out pretty good. Your
prolific contribution to the group is appreciated!

I've got the scope out waiting to see how Mars looks tonight. A little
steadyness is all I need!

Cheers,

Rick Johnson wrote:
Here is is mostly no photons. Right now there's 18" of snow on the
roof. I need to get that off before I can even roll it. At -14F
right now I don't see that happening. Normally the Polaris tree
greatly limits snowfall on the roof but this year all our storms have
come from the south. Never seen that in the years we've lived here.
First year temps ever got above freezing this month. The garage with
my truck faces south so when we hit 34F the water all flowed against
the door. It is sealed by 4" of solid ice. I'll need a jack hammer to
get that door open before March. Hope I don't need the truck.
Probably have lots of ice in the roof track as well. Until I get that
snow off I won't know. Rolling the roof can cause it to suddenly
avalanche into the observatory. Did that the first winter. No fun
shoveling all that snow over a 6 foot wall!

As for more time I've found it of very little help. Even tripling the
time does little to increase depth. Noise level improves a lot so the
image is far less grainy but faint stuff just doesn't seem to show any
better, just a lot easier to process it. With so many targets and so
little scope time due to weather I've chose to put the time into the
processing end. I suppose if I would quadruple the time I might see
some gain but from the only slight improvement doubling gave I just
don't see it happening. What I really need is better transparency.
On an average night I reach about 22.5 mag objects but on a good night
I can go past 24! That's one heck of a difference. Far more than I'd
expect. Yet that's what the measurements show. Seeing helps a bit
but I'm talking galaxies with a size at least that of the seeing not
point sources. Get one of those nights and then I will consider more
time as then it does make a difference. Unfortunately they are rare.

Rick

Adriano wrote:

This is a fine image Rick, neat pair indeed. Wish I could see those
faint filaments a bit better though, you should be less chintzy on
the L ;-)

Clear skies!

P.S. All my Mars stuff has been a wash so far; poor seeing or no
seeing

Rick Johnson wrote:

Arp 294 is an interacting pair of galaxies about 135 million
light-years distant in southern Ursa Major.


SNIP


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

Rick








--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Rick,

amazing how consistently you get very good detail in small galaxies. Looks
like you had some good seeing in April.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
. com...
Arp 294 is an interacting pair of galaxies about 135 million light-years
distant in southern Ursa Major. It appears the upper one is about to
ram into the lower though this isn't likely the case at all. The image
did remind me of a much criticized line in the B5 series when a
spaceship Captain ordered "ramming speed". Arp classified them under
Group Character: Long filaments. I'd have classed it under Wind Effects
but it isn't my catalog. While the northern galaxy, NGC 3788, does have
a long filament that is typical of tidal interaction, the lower galaxy,
NGC 3786, has two rather unusual filaments that look a bit "wind blown".
They are likely tidally created however. Arp did see these as his
comment on the pair is simply; "Peculiar filaments." NGC 3786 is
classified as (R')SAB(r)a pec and has an active nucleus that appears to
be a Seyfert 1. NGC 3788 is classed as SAB(rs)ab pec. Both shine at
13th magnitude so should be visible in an 8" scope under dark skies.
The filaments however may challenge even the largest scopes.

The small galaxy just below NGC 3786 is SDSS J113939.20+315320.4 at 460
million light-years. The red vertical spindle galaxy east of NGC 3788 is
SDSS J114002.67+315607.1 is about 780 million light-years distant.

The spiral galaxy about 5 minutes of arc south west of Arp 294 is CGCG
157-007 about 400 million light-years away. It appears rather distorted
with tidal debris. This interaction must have happened some time ago as
there are no obvious nearby candidates for a partner. The "small"
galaxy to its west is SDSS J113918.50+315121 at 1 billion light-years.
Far too distant to be involved. Further west of it is the even
"smaller" galaxy SDSS J113912.92+315120.5 at 1.6 billion light-years.

The galaxies and quasars I was able to find red shift data on at NED are
shown on the annotated image. The most distant galaxy is 5.3 billion
light-years distant shining at fainter than 21st magnitude so at about
my limit on this image. Quasars range from just 2.9 to 12 billion
light-years.

SDSS image:
http://astronomerica.awardspace.com/.../NGC3786-8.php

The SDSS page makes reference to NGC 3793 as being CGCG 157-007. This
is wrong. NGC 3793 is a single star east, not west of Arp 294.
To find it on the SDSS image go from NGC 3786 to the bright red star
then continue almost of the same line about the same distance to this
rather bright star. It is directly below the vertical spindle of SDSS
J114002.67+315607.1 mentioned above. NGC 3797 is also a star in my
image but just out of the frame of the SDSS image. For a more complete
discussion of this mix-up see the NGC project entry for NGC 3793.
http://www.ngcicproject.org/dss/dss_n3700.asp I can't explain why the
very red star in the Sloan image is white with a blue halo in my shot.
SDSS uses three IR filters along with three visual band filters and it
could be those colors are so strong they skew the color to red. Very
bright stars cause blue halos in my filters but the star in question is
spectral class G0 so a pretty white star in reality. It is GSC
2523:1968/HIP 56900 for those who want to look it up.

This is my last April image (29th UTC). Moving to May. May was mostly
cloudy so only 3 images taken in May, all Arp galaxies.

Arp's image:
http://nedwww.ipac.caltech.edu/level...ig_arp294.jpeg

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

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

Yes, I got lucky this spring with a few weeks of pretty good seeing.
Not quite enough to go to 0.5" unbinned however. I'm paying for it now
however. Nothing but clouds or full moon. If it does clear
transparency and seeing are awful. Most nights I've been able to
collect a photon or two through the gunk have had 3.5" seeing, not the
2.5 of these images. Very disappointing.

Rick


Stefan Lilge wrote:
Rick,

amazing how consistently you get very good detail in small galaxies. Looks
like you had some good seeing in April.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
. com...
Arp 294 is an interacting pair of galaxies about 135 million light-years
distant in southern Ursa Major. It appears the upper one is about to
ram into the lower though this isn't likely the case at all. The image
did remind me of a much criticized line in the B5 series when a
spaceship Captain ordered "ramming speed". Arp classified them under
Group Character: Long filaments. I'd have classed it under Wind Effects
but it isn't my catalog. While the northern galaxy, NGC 3788, does have
a long filament that is typical of tidal interaction, the lower galaxy,
NGC 3786, has two rather unusual filaments that look a bit "wind blown".
They are likely tidally created however. Arp did see these as his
comment on the pair is simply; "Peculiar filaments." NGC 3786 is
classified as (R')SAB(r)a pec and has an active nucleus that appears to
be a Seyfert 1. NGC 3788 is classed as SAB(rs)ab pec. Both shine at
13th magnitude so should be visible in an 8" scope under dark skies.
The filaments however may challenge even the largest scopes.

The small galaxy just below NGC 3786 is SDSS J113939.20+315320.4 at 460
million light-years. The red vertical spindle galaxy east of NGC 3788 is
SDSS J114002.67+315607.1 is about 780 million light-years distant.

The spiral galaxy about 5 minutes of arc south west of Arp 294 is CGCG
157-007 about 400 million light-years away. It appears rather distorted
with tidal debris. This interaction must have happened some time ago as
there are no obvious nearby candidates for a partner. The "small"
galaxy to its west is SDSS J113918.50+315121 at 1 billion light-years.
Far too distant to be involved. Further west of it is the even
"smaller" galaxy SDSS J113912.92+315120.5 at 1.6 billion light-years.

The galaxies and quasars I was able to find red shift data on at NED are
shown on the annotated image. The most distant galaxy is 5.3 billion
light-years distant shining at fainter than 21st magnitude so at about
my limit on this image. Quasars range from just 2.9 to 12 billion
light-years.

SDSS image:
http://astronomerica.awardspace.com/.../NGC3786-8.php

The SDSS page makes reference to NGC 3793 as being CGCG 157-007. This
is wrong. NGC 3793 is a single star east, not west of Arp 294.
To find it on the SDSS image go from NGC 3786 to the bright red star
then continue almost of the same line about the same distance to this
rather bright star. It is directly below the vertical spindle of SDSS
J114002.67+315607.1 mentioned above. NGC 3797 is also a star in my
image but just out of the frame of the SDSS image. For a more complete
discussion of this mix-up see the NGC project entry for NGC 3793.
http://www.ngcicproject.org/dss/dss_n3700.asp I can't explain why the
very red star in the Sloan image is white with a blue halo in my shot.
SDSS uses three IR filters along with three visual band filters and it
could be those colors are so strong they skew the color to red. Very
bright stars cause blue halos in my filters but the star in question is
spectral class G0 so a pretty white star in reality. It is GSC
2523:1968/HIP 56900 for those who want to look it up.

This is my last April image (29th UTC). Moving to May. May was mostly
cloudy so only 3 images taken in May, all Arp galaxies.

Arp's image:
http://nedwww.ipac.caltech.edu/level...ig_arp294.jpeg

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

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".





--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".