ASTRO: Arp 96

Arp 96 falls under Arp's category for spiral galaxies with elliptical
galaxies on their arms. They are located 205 million light-years away
based on their redshifts which are virtually identical. But we can't
say the elliptical is on the arm of the spiral. It would be better to
say it appears to be on the arm. If it really were I suspect the arm
(more a plume) would be more highly distorted. Arp stated his
categories as if they were fact when they were more how they appeared to
him. In some cases the galaxy on a spiral's arm is now known to be a
far distant galaxy. His other categories were often incorrect.
Especially those that he said categorized as material ejected from the
nucleus. That's not true for any in that category that I've been able
to determine.

Arp's comment on this pair reads: "Faint Diffuse counter arm, and arm
leading to companion." These don't follow the curve of the two arms of
the spiral galaxy and lie beyond them. They appear even more diffuse
than the spiral which is surprisingly diffuse for a spiral to begin
with. I could call them plumes rather than arms. It appears to be an
old spiral in which star formation ceased several billion years ago
turning it somewhat red in color as the bluer stars have all burned out
and turned to faint white dwarfs, pulsars etc. that give off little
light. Since it is usually the hot blue stars that give a spiral its
highly detailed features it isn't surprising that without them it looks
awfully fuzzy. This could be the result of an interaction far older
than its encounter with the current elliptical companion.

This pair is known as UGC 03536B/MCG +14-04-10 (spiral) and UGC
3536A/MCG +14-04-11 (elliptical). NED says the spiral is Sc while the
Elliptical is just listed as E or E? A note at NED says of it: "Compact
symmetrical object with red envelope." The pair is located in Cepheus
only 3.4 degrees from the pole. Certainly it would qualify as the Arp
North Pole Galaxy. Imaging this close to the pole is testament to how
precisely I've achieved polar alignment. It takes extreme accuracy to
go for two hours without image rotation at this declination as any who
have tried it can attest. Until the storm took out my two Polaris trees
I'd not been able to do any imaging in this part of the sky. The Arp
25-114 pair is less than a degree further from the pole. While very
nearby I didn't get around to it until January 2012 so it will be a
while before I process it. About 30 are ahead if it. This close to the
pole I can ignore my rule of sticking within 2 hours of the meridian as
it makes very little difference.

Actually this is a triple galaxy in the WBL (White+Bliton+Bhavsar
groups) and KTG (Karachentsev Isolated Triplets of Galaxies Catalogue)
catalogs. The third galaxy is CGCG 362-033/MCG +14-04-014/PGC 020191
among other designations. It is the obvious spiral to the northeast. It
is listed as Sa in NED. It appears to have a ring structure in my image
not mentioned in the classification. This may be due to my resolution
and when seen at higher resolution not a ring at all. I was unable to
find any images of it on the net with even as much resolution as I have.

No other galaxy in the image has a redshift at NED so I didn't prepare
an annotated image.

This image was taken at 0.5" per pixel. The image has been cropped
however as even cropped it is 3006x2004 pixels in size. These galaxies
are quite small in angular size and I took advantage of one of the very
rare nights when this was possible. I've also included a crop at 2004
pixels wide same as my normal 1" per pixel images for those who prefer
it smaller.

Arp's image of the pair is at:
http://ned.ipac.caltech.edu/level5/A...big_arp96.jpeg
For his image he used 103a-D film. I used a lot of it in my film days
before 2415 film was available. Still had a roll in my freezer when I
gave up film work. I threw it out as it was about 20 years old as I'd
changed to hypered 2415 years before. It is rather well matched to the
human eye for its response covering 4700 to 6000 angstroms. So lops off
the blue and red ends of the spectrum passing mostly the region our eye
is most sensitive. Arp used no filter. Since these galaxies are
somewhat red I'd have expected him to have used 103a-E which is more red
sensitive.

14" LX200R @ f/10, L=6x10'x1 RGB=2x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net

Rick,

the "S"-shaped galaxy is a beauty!

Stefan

"Rick Johnson" schrieb im Newsbeitrag
.com...

Arp 96 falls under Arp's category for spiral galaxies with elliptical
galaxies on their arms. They are located 205 million light-years away
based on their redshifts which are virtually identical. But we can't
say the elliptical is on the arm of the spiral. It would be better to
say it appears to be on the arm. If it really were I suspect the arm
(more a plume) would be more highly distorted. Arp stated his
categories as if they were fact when they were more how they appeared to
him. In some cases the galaxy on a spiral's arm is now known to be a
far distant galaxy. His other categories were often incorrect.
Especially those that he said categorized as material ejected from the
nucleus. That's not true for any in that category that I've been able
to determine.

Arp's comment on this pair reads: "Faint Diffuse counter arm, and arm
leading to companion." These don't follow the curve of the two arms of
the spiral galaxy and lie beyond them. They appear even more diffuse
than the spiral which is surprisingly diffuse for a spiral to begin
with. I could call them plumes rather than arms. It appears to be an
old spiral in which star formation ceased several billion years ago
turning it somewhat red in color as the bluer stars have all burned out
and turned to faint white dwarfs, pulsars etc. that give off little
light. Since it is usually the hot blue stars that give a spiral its
highly detailed features it isn't surprising that without them it looks
awfully fuzzy. This could be the result of an interaction far older
than its encounter with the current elliptical companion.

This pair is known as UGC 03536B/MCG +14-04-10 (spiral) and UGC
3536A/MCG +14-04-11 (elliptical). NED says the spiral is Sc while the
Elliptical is just listed as E or E? A note at NED says of it: "Compact
symmetrical object with red envelope." The pair is located in Cepheus
only 3.4 degrees from the pole. Certainly it would qualify as the Arp
North Pole Galaxy. Imaging this close to the pole is testament to how
precisely I've achieved polar alignment. It takes extreme accuracy to
go for two hours without image rotation at this declination as any who
have tried it can attest. Until the storm took out my two Polaris trees
I'd not been able to do any imaging in this part of the sky. The Arp
25-114 pair is less than a degree further from the pole. While very
nearby I didn't get around to it until January 2012 so it will be a
while before I process it. About 30 are ahead if it. This close to the
pole I can ignore my rule of sticking within 2 hours of the meridian as
it makes very little difference.

Actually this is a triple galaxy in the WBL (White+Bliton+Bhavsar
groups) and KTG (Karachentsev Isolated Triplets of Galaxies Catalogue)
catalogs. The third galaxy is CGCG 362-033/MCG +14-04-014/PGC 020191
among other designations. It is the obvious spiral to the northeast. It
is listed as Sa in NED. It appears to have a ring structure in my image
not mentioned in the classification. This may be due to my resolution
and when seen at higher resolution not a ring at all. I was unable to
find any images of it on the net with even as much resolution as I have.

No other galaxy in the image has a redshift at NED so I didn't prepare
an annotated image.

This image was taken at 0.5" per pixel. The image has been cropped
however as even cropped it is 3006x2004 pixels in size. These galaxies
are quite small in angular size and I took advantage of one of the very
rare nights when this was possible. I've also included a crop at 2004
pixels wide same as my normal 1" per pixel images for those who prefer
it smaller.

Arp's image of the pair is at:
http://ned.ipac.caltech.edu/level5/A...big_arp96.jpeg
For his image he used 103a-D film. I used a lot of it in my film days
before 2415 film was available. Still had a roll in my freezer when I
gave up film work. I threw it out as it was about 20 years old as I'd
changed to hypered 2415 years before. It is rather well matched to the
human eye for its response covering 4700 to 6000 angstroms. So lops off
the blue and red ends of the spectrum passing mostly the region our eye
is most sensitive. Arp used no filter. Since these galaxies are
somewhat red I'd have expected him to have used 103a-E which is more red
sensitive.

14" LX200R @ f/10, L=6x10'x1 RGB=2x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net