ASTRO: NGC 974 et al

This is an image of a group of galaxies, including 6 NGC galaxies (4
entries in the catalog) and others in the field. The group is located
in Triangulum about 200 million light-years away. At least the major
galaxies are at that distance. Are they related? It appears two NGC
969 and NGC 974 may be interacting. NGC 969 is classed as S0 but
appears to be a SB0 to me or maybe even SBa. It is obviously somewhat
torn apart as stars are sprayed everywhere. NGC 974 is a ring type
spiral with faint arms coming off of a rather football shaped ring. The
western arm is rather well defined while the eastern one is a mess. It
has a hint of a bar so is classed SAB(rs)b. Between these two is NGC
970 with consists of a pair of elliptical like galaxies in a common
envelope. Is that the case or is one in front of the other with their
star balls overlapping? There's no redshift data on this one so we
don't even know if they are related to the first two. They certainly
would fit Arp's classification for galaxies with the appearance of
fission. In this case mitosis might be the better term.

Even more confusing is the case of NGC 971. The Sky says it is a double
star. The annotated image has a line drawn to a point half way between
the two stars. The NGC project is quite confused about this one. In
the finder image they point to a rather bright orange star below the
double star. But they give the coordinates for a position 28" north of
the double star but with the same RA as the star. NED also says it is a
star but gives the same wrong coordinates as the NGC Project. The NGC
Project says "Lord Rosse's diagram and micrometric measurements with
respect to NGC 970 point exactly to the star." Likely some error has
misstated the stars declination. I put in three lines drawn to these
three spots. In any case it isn't a galaxy.

The remaining NGC object is NGC 978, another double galaxy. Both are
classed as S0. The large upper galaxy has a red shift that puts it at
207 million light years while the small southern one is at 189 million
light years. Likely they are much closer with the difference being due
to relative motion. Neither appear distorted and the little one seems
to hide the fainter portions of the large one as well as darken it so
I'll assume it is in front of the larger galaxy as redshift would
indicate. I see little to indicate interaction so doubt they have come
very close to each other though it's possible they will in the future.
To darken the galaxy behind it has to have significant dust in its disk,
rather rare for SO galaxies.

There are only 2 other galaxies in the image with redshift data. CGCG
505-008 appears double though one of the cores is likely a star. Which
is the star is the question. Since the cores of such objects tend to be
red I'm going to say it is the eastern (left) one but my color data is
poor (more on that in a bit). NED's position is half way between the
two as if it sees this as one object.

Of more interest is NPM1G +32.0101. It is not classified by NED. It
appears to be a double ring barred spiral. A very unusual galaxy. That
outer ring is hard to explain, at least for me. Any ideas out there how
this could happen?

The field is little studied. I've labeled all easily seen galaxies
listed in NED. I left out three very low surface brightness galaxies
that show as very faint smudges in my image. I did pick up one. NGC
1023 GROUP:[TT2009] 39. The other three carry this same catalog prefix,
only the number at the end is different. Normally NED will explain a
catalog name but it refuses in this case. I have no idea what it means.
NGC 1023 is over 6 degrees north and a bit east of my field and in
Camelopardalis. Many rather bright galaxies aren't even listed in NED.
I've marked a few with a question mark as they seem much brighter than
many it did include. The omitted ones likely didn't make the 2MASS
catalog. One did make the 2MASS flat galaxy catalog, 2MFGC 02031. The
Flat Galaxy Catalog requires galaxies be very flat for listing. It
appears the 2MASS Flat Galaxy Catalog is far more lenient as to who it
admits to its catalog.

Clouds made a mess of this one. I almost didn't even try to process it.
Blue frames were totally lost to clouds, one luminance frame was very
weak and foggy but I did include it as it seemed to help to do so but
only if I used a noise rejection stack. These, I've not had much luck
with when only having 4 with one pretty lousy. But it worked better
than 3 (cost me some asteroids however) so went with it. Now about the
missing blue. There's a technique for creating green from a red and
blue image. This is used to make color images from the DSS plates for
instance. I did a similar math process but extended it out rather than
interpolating an in-between value. Thus my color is suspect. Still I
think it rather accurate. This one is on on the reshoot list more for
more time to pick up the fainter tidal sprays I missed due to the thick
haze and gunk I was imaging through. The way this winter is going it
might not happen this year. Weather here is awful and I thought it bad
last year!

14" LX200R @ f/10, L=4x10' RG=2x10x3 B interpolated from the R and G,
STL-11000XM, Paramount ME

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

Beautiful image Rick. Colour looks very good in spite of the missing blue
channel.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
ter.com...
This is an image of a group of galaxies, including 6 NGC galaxies (4
entries in the catalog) and others in the field. The group is located
in Triangulum about 200 million light-years away. At least the major
galaxies are at that distance. Are they related? It appears two NGC
969 and NGC 974 may be interacting. NGC 969 is classed as S0 but
appears to be a SB0 to me or maybe even SBa. It is obviously somewhat
torn apart as stars are sprayed everywhere. NGC 974 is a ring type
spiral with faint arms coming off of a rather football shaped ring. The
western arm is rather well defined while the eastern one is a mess. It
has a hint of a bar so is classed SAB(rs)b. Between these two is NGC
970 with consists of a pair of elliptical like galaxies in a common
envelope. Is that the case or is one in front of the other with their
star balls overlapping? There's no redshift data on this one so we
don't even know if they are related to the first two. They certainly
would fit Arp's classification for galaxies with the appearance of
fission. In this case mitosis might be the better term.

Even more confusing is the case of NGC 971. The Sky says it is a double
star. The annotated image has a line drawn to a point half way between
the two stars. The NGC project is quite confused about this one. In
the finder image they point to a rather bright orange star below the
double star. But they give the coordinates for a position 28" north of
the double star but with the same RA as the star. NED also says it is a
star but gives the same wrong coordinates as the NGC Project. The NGC
Project says "Lord Rosse's diagram and micrometric measurements with
respect to NGC 970 point exactly to the star." Likely some error has
misstated the stars declination. I put in three lines drawn to these
three spots. In any case it isn't a galaxy.

The remaining NGC object is NGC 978, another double galaxy. Both are
classed as S0. The large upper galaxy has a red shift that puts it at
207 million light years while the small southern one is at 189 million
light years. Likely they are much closer with the difference being due
to relative motion. Neither appear distorted and the little one seems
to hide the fainter portions of the large one as well as darken it so
I'll assume it is in front of the larger galaxy as redshift would
indicate. I see little to indicate interaction so doubt they have come
very close to each other though it's possible they will in the future.
To darken the galaxy behind it has to have significant dust in its disk,
rather rare for SO galaxies.

There are only 2 other galaxies in the image with redshift data. CGCG
505-008 appears double though one of the cores is likely a star. Which
is the star is the question. Since the cores of such objects tend to be
red I'm going to say it is the eastern (left) one but my color data is
poor (more on that in a bit). NED's position is half way between the
two as if it sees this as one object.

Of more interest is NPM1G +32.0101. It is not classified by NED. It
appears to be a double ring barred spiral. A very unusual galaxy. That
outer ring is hard to explain, at least for me. Any ideas out there how
this could happen?

The field is little studied. I've labeled all easily seen galaxies
listed in NED. I left out three very low surface brightness galaxies
that show as very faint smudges in my image. I did pick up one. NGC
1023 GROUP:[TT2009] 39. The other three carry this same catalog prefix,
only the number at the end is different. Normally NED will explain a
catalog name but it refuses in this case. I have no idea what it means.
NGC 1023 is over 6 degrees north and a bit east of my field and in
Camelopardalis. Many rather bright galaxies aren't even listed in NED.
I've marked a few with a question mark as they seem much brighter than
many it did include. The omitted ones likely didn't make the 2MASS
catalog. One did make the 2MASS flat galaxy catalog, 2MFGC 02031. The
Flat Galaxy Catalog requires galaxies be very flat for listing. It
appears the 2MASS Flat Galaxy Catalog is far more lenient as to who it
admits to its catalog.

Clouds made a mess of this one. I almost didn't even try to process it.
Blue frames were totally lost to clouds, one luminance frame was very
weak and foggy but I did include it as it seemed to help to do so but
only if I used a noise rejection stack. These, I've not had much luck
with when only having 4 with one pretty lousy. But it worked better
than 3 (cost me some asteroids however) so went with it. Now about the
missing blue. There's a technique for creating green from a red and
blue image. This is used to make color images from the DSS plates for
instance. I did a similar math process but extended it out rather than
interpolating an in-between value. Thus my color is suspect. Still I
think it rather accurate. This one is on on the reshoot list more for
more time to pick up the fainter tidal sprays I missed due to the thick
haze and gunk I was imaging through. The way this winter is going it
might not happen this year. Weather here is awful and I thought it bad
last year!

14" LX200R @ f/10, L=4x10' RG=2x10x3 B interpolated from the R and G,
STL-11000XM, Paramount ME

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