ASTRO: NGC 2381 A face on spiral

NGC 2381 is a rather odd spiral galaxy in Ursa Major some 40 to 50
million light-years distant. NED gives it the very complex
classification as (R')SAB(rs)0/a Sy3 while the NGC project says simply
Sa. Notes at NED say it has 3 bars and three stellar points in the core
all within one kiloparsec (3260) light-years. That would be 13 to 17
pixels in my image but I see no hint of these in my image. Resolution
far to low I suspect. It appears to have undergone a starburst in the
core similar to that we currently see in M82 but it is long over in this
galaxy as it is dated to a billion years ago. Most likely it is due to
the influx of dust and gas from a companion it digested. If all those
bars and stellar points near the center are any indication it may have
feasted several times. Some papers call it a LINER galaxy while others
say a Low Luminosity Active Galactic Nucleus galaxy. NED says Seyfert
3. In any case the black hole it harbors is still feeding at a steady
but low level. http://adsabs.harvard.edu/abs/2001ApJ...551..197C

There's one apparent companion to NGC 2381 in the image; MCG +09-15-039
has about the same redshift. Unfortunately, NED has nothing else on it.

NGC 2381 is a rather small spiral being only about 40,000 light-years
across if the 40 million light-year distance is correct and 50,000
light-years across if the 50 million light-year estimate is correct.
But MCG +09-15-039 is tiny at 9300 light years across at its 35 million
light-year distance. Both these would argue they are further away than
their redshift indicates. At the top of the image is a nice spiral at a
distance of 760,000 light-years. It is nearly 100,000 light-years
across at that distance. That would make it similar in size to our own.
Ours would look much the same of there's someone in that galaxy
looking back at us.

There are a lot of other galaxies in the image. Those with redshift
data are labeled. The few with catalog names other than those that just
list its coordinates are also listed by their most common catalog
designation. There seems to be a scattering of galaxies at about
960,000 light years across the image. If their redshift is
photometrically determined a "p" is placed after the distance. These
are usually less reliable than spectroscopic determinations. Several
galaxy clusters are noted. Usually the position is the same as the
anchoring "Big Cluster Galaxy" so I made only one annotation work for
both. If the position of the cluster's center is different then a line
is drawn to that point on the image.

Those objects designated as Ultra violet Excess Sources (UvES) are all
quasar candidates. All seem to have only photometric redshifts available.

Due to poor seeing the cropped image is at 0.8" per pixel.

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

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

For some reason I kept saying NGC 2381 when it is 2681. The annotated
image is correct. Here's the corrected text.
NGC 2681 is a rather odd spiral galaxy in Ursa Major some 40 to 50
million light-years distant. NED gives it the very complex
classification as (R')SAB(rs)0/a Sy3 while the NGC project says simply
Sa. Notes at NED say it has 3 bars and three stellar points in the core
all within one kiloparsec (3260) light-years. That would be 13 to 17
pixels in my image but I see no hint of these in my image. Resolution
far to low I suspect. It appears to have undergone a starburst in the
core similar to that we currently see in M82 but it is long over in this
galaxy as it is dated to a billion years ago. Most likely it is due to
the influx of dust and gas from a companion it digested. If all those
bars and stellar points near the center are any indication it may have
feasted several times. Some papers call it a LINER galaxy while others
say a Low Luminosity Active Galactic Nucleus galaxy. NED says Seyfert
3. In any case the black hole it harbors is still feeding at a steady
but low level. http://adsabs.harvard.edu/abs/2001ApJ...551..197C

There's one apparent companion to NGC 2681 in the image; MCG +09-15-039
has about the same redshift. Unfortunately, NED has nothing else on it.

NGC 2681 is a rather small spiral being only about 40,000 light-years
across if the 40 million light-year distance is correct and 50,000
light-years across if the 50 million light-year estimate is correct.
But MCG +09-15-039 is tiny at 9300 light years across at its 35 million
light-year distance. Both these would argue they are further away than
their redshift indicates. At the top of the image is a nice spiral at a
distance of 760,000 light-years. It is nearly 100,000 light-years
across at that distance. That would make it similar in size to our own.
Ours would look much the same of there's someone in that galaxy
looking back at us.

There are a lot of other galaxies in the image. Those with redshift
data are labeled. The few with catalog names other than those that just
list its coordinates are also listed by their most common catalog
designation. There seems to be a scattering of galaxies at about
960,000 light years across the image. If their redshift is
photometrically determined a "p" is placed after the distance. These
are usually less reliable than spectroscopic determinations. Several
galaxy clusters are noted. Usually the position is the same as the
anchoring "Big Cluster Galaxy" so I made only one annotation work for
both. If the position of the cluster's center is different then a line
is drawn to that point on the image.

Those objects designated as Ultra violet Excess Sources (UvES) are all
quasar candidates. All seem to have only photometric redshifts available.

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

Rick

--
Prefix is correct. Domain is arvig dot net

Rick,

at last a galaxy that I don't need to put on my list as I already have it
;-)
You got both good depth and detail in this image.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

NGC 2381 is a rather odd spiral galaxy in Ursa Major some 40 to 50
million light-years distant. NED gives it the very complex
classification as (R')SAB(rs)0/a Sy3 while the NGC project says simply
Sa. Notes at NED say it has 3 bars and three stellar points in the core
all within one kiloparsec (3260) light-years. That would be 13 to 17
pixels in my image but I see no hint of these in my image. Resolution
far to low I suspect. It appears to have undergone a starburst in the
core similar to that we currently see in M82 but it is long over in this
galaxy as it is dated to a billion years ago. Most likely it is due to
the influx of dust and gas from a companion it digested. If all those
bars and stellar points near the center are any indication it may have
feasted several times. Some papers call it a LINER galaxy while others
say a Low Luminosity Active Galactic Nucleus galaxy. NED says Seyfert
3. In any case the black hole it harbors is still feeding at a steady
but low level. http://adsabs.harvard.edu/abs/2001ApJ...551..197C

There's one apparent companion to NGC 2381 in the image; MCG +09-15-039
has about the same redshift. Unfortunately, NED has nothing else on it.

NGC 2381 is a rather small spiral being only about 40,000 light-years
across if the 40 million light-year distance is correct and 50,000
light-years across if the 50 million light-year estimate is correct.
But MCG +09-15-039 is tiny at 9300 light years across at its 35 million
light-year distance. Both these would argue they are further away than
their redshift indicates. At the top of the image is a nice spiral at a
distance of 760,000 light-years. It is nearly 100,000 light-years
across at that distance. That would make it similar in size to our own.
Ours would look much the same of there's someone in that galaxy
looking back at us.

There are a lot of other galaxies in the image. Those with redshift
data are labeled. The few with catalog names other than those that just
list its coordinates are also listed by their most common catalog
designation. There seems to be a scattering of galaxies at about
960,000 light years across the image. If their redshift is
photometrically determined a "p" is placed after the distance. These
are usually less reliable than spectroscopic determinations. Several
galaxy clusters are noted. Usually the position is the same as the
anchoring "Big Cluster Galaxy" so I made only one annotation work for
both. If the position of the cluster's center is different then a line
is drawn to that point on the image.

Those objects designated as Ultra violet Excess Sources (UvES) are all
quasar candidates. All seem to have only photometric redshifts available.

Due to poor seeing the cropped image is at 0.8" per pixel.

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

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