ASTRO: UGC 2023

UGC 2023 is a very faint irregular galaxy in eastern Triangulum. It's
distance is rather vague. Redshift says 17 million light-years while
Tully Fisher says almost twice that, 33 million light-years. I don't
trust such close redshift values so will say the larger value is likely
closer to being correct but the error bar is quite high. NED classes it
as Im?

When I was researching NGC 925 which lies about 1.25 degrees west I
found it too had a red shift of about the same as UGC 2023 and was
listed with widely varying distances centering on about 30 million
light-years. Yet there were several others with similar redshifts
arguing for half that distance. As I mentioned with NGC 925 neither
seem to have the resolution I'd expect for the closer distance. Still
the common redshift would at least indicate they are likely part of a
group. The group may just be moving as a unit away from us more slowly
than expansion redshift alone would be.

I needed much more time to really do this one justice. It is unusually
low surface brightness so darned faint. NGC 925 is also considered a
low surface brightness galaxy, spiral rather than irregular. I've not
looked into the others in the group.

NED has no redshift for any other galaxy in the field. This is a little
studied area. There's an interesting very flat galaxy to the north
northeast of UGC 2023 that's quite blue. It's not listed in NED. It
points down and to the left toward what appears to be a string of very
distant galaxies, likely a cluster following the line started by the
flat galaxy and ending with a red S0 looking rather "bright" galaxy, at
least bright for this field. I found nothing on the distant galaxies.
The red galaxy is 2MASX J02340198+3332226 but it doesn't even have a
magnitude estimate or anything else useful.

I am a bit puzzled by an odd star in the upper left quadrant. It has a
very unusual red ring around it. I've had some deep red stars have red
halos but this is an H alpha red, very different from the red halo I
occasionally see around red stars due to seeing issues. The star is TYC
2328-1008-1 with a B-V of 0.55. That's a rather white star (our sun is
0.66 or a bit redder than this star), far from red like the halo. It is
listed in SIMBAD at a V magnitude of 12.43. My quick and dirty
measurement says 12.44 while The Sky says it is 11.4. I can't explain
why The Sky and SIMBAD don't agree but this is very common. In any case
with my magnitude and SIMBAD's the same it would seem nothing odd is
going on so what is it with the red halo? I can't find any color images
of the area. The POSS 2 plates do show it a bit brighter in red than
blue light but I see no sign of that odd halo I picked up. Could be
just dirt on a surface I suppose. I want to retake the color data this
year (taken September 30, 2011) and see if it reappears. So far the
weather hasn't cooperated.

The entire field seems to have a faint hint of galactic cirrus. I've
picked it up in other images in this area.

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

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

This one was in dire need of reprocessing. Here's a cropped, and enlarged to 0.67" per pixel revised version and the full frame at 1" per pixel.
Rick

Originally Posted by Rick Johnson[_2_]

UGC 2023 is a very faint irregular galaxy in eastern Triangulum. It's
distance is rather vague. Redshift says 17 million light-years while
Tully Fisher says almost twice that, 33 million light-years. I don't
trust such close redshift values so will say the larger value is likely
closer to being correct but the error bar is quite high. NED classes it
as Im?

When I was researching NGC 925 which lies about 1.25 degrees west I
found it too had a red shift of about the same as UGC 2023 and was
listed with widely varying distances centering on about 30 million
light-years. Yet there were several others with similar redshifts
arguing for half that distance. As I mentioned with NGC 925 neither
seem to have the resolution I'd expect for the closer distance. Still
the common redshift would at least indicate they are likely part of a
group. The group may just be moving as a unit away from us more slowly
than expansion redshift alone would be.

I needed much more time to really do this one justice. It is unusually
low surface brightness so darned faint. NGC 925 is also considered a
low surface brightness galaxy, spiral rather than irregular. I've not
looked into the others in the group.

NED has no redshift for any other galaxy in the field. This is a little
studied area. There's an interesting very flat galaxy to the north
northeast of UGC 2023 that's quite blue. It's not listed in NED. It
points down and to the left toward what appears to be a string of very
distant galaxies, likely a cluster following the line started by the
flat galaxy and ending with a red S0 looking rather "bright" galaxy, at
least bright for this field. I found nothing on the distant galaxies.
The red galaxy is 2MASX J02340198+3332226 but it doesn't even have a
magnitude estimate or anything else useful.

I am a bit puzzled by an odd star in the upper left quadrant. It has a
very unusual red ring around it. I've had some deep red stars have red
halos but this is an H alpha red, very different from the red halo I
occasionally see around red stars due to seeing issues. The star is TYC
2328-1008-1 with a B-V of 0.55. That's a rather white star (our sun is
0.66 or a bit redder than this star), far from red like the halo. It is
listed in SIMBAD at a V magnitude of 12.43. My quick and dirty
measurement says 12.44 while The Sky says it is 11.4. I can't explain
why The Sky and SIMBAD don't agree but this is very common. In any case
with my magnitude and SIMBAD's the same it would seem nothing odd is
going on so what is it with the red halo? I can't find any color images
of the area. The POSS 2 plates do show it a bit brighter in red than
blue light but I see no sign of that odd halo I picked up. Could be
just dirt on a surface I suppose. I want to retake the color data this
year (taken September 30, 2011) and see if it reappears. So far the
weather hasn't cooperated.

The entire field seems to have a faint hint of galactic cirrus. I've
picked it up in other images in this area.

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

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

Rick,

there are some nice blue knots in this dwarf.
The strange star looks like purple fringing of an achromat, which obviously
is not the reason for it's appearance.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

UGC 2023 is a very faint irregular galaxy in eastern Triangulum. It's
distance is rather vague. Redshift says 17 million light-years while
Tully Fisher says almost twice that, 33 million light-years. I don't
trust such close redshift values so will say the larger value is likely
closer to being correct but the error bar is quite high. NED classes it
as Im?

When I was researching NGC 925 which lies about 1.25 degrees west I
found it too had a red shift of about the same as UGC 2023 and was
listed with widely varying distances centering on about 30 million
light-years. Yet there were several others with similar redshifts
arguing for half that distance. As I mentioned with NGC 925 neither
seem to have the resolution I'd expect for the closer distance. Still
the common redshift would at least indicate they are likely part of a
group. The group may just be moving as a unit away from us more slowly
than expansion redshift alone would be.

I needed much more time to really do this one justice. It is unusually
low surface brightness so darned faint. NGC 925 is also considered a
low surface brightness galaxy, spiral rather than irregular. I've not
looked into the others in the group.

NED has no redshift for any other galaxy in the field. This is a little
studied area. There's an interesting very flat galaxy to the north
northeast of UGC 2023 that's quite blue. It's not listed in NED. It
points down and to the left toward what appears to be a string of very
distant galaxies, likely a cluster following the line started by the
flat galaxy and ending with a red S0 looking rather "bright" galaxy, at
least bright for this field. I found nothing on the distant galaxies.
The red galaxy is 2MASX J02340198+3332226 but it doesn't even have a
magnitude estimate or anything else useful.

I am a bit puzzled by an odd star in the upper left quadrant. It has a
very unusual red ring around it. I've had some deep red stars have red
halos but this is an H alpha red, very different from the red halo I
occasionally see around red stars due to seeing issues. The star is TYC
2328-1008-1 with a B-V of 0.55. That's a rather white star (our sun is
0.66 or a bit redder than this star), far from red like the halo. It is
listed in SIMBAD at a V magnitude of 12.43. My quick and dirty
measurement says 12.44 while The Sky says it is 11.4. I can't explain
why The Sky and SIMBAD don't agree but this is very common. In any case
with my magnitude and SIMBAD's the same it would seem nothing odd is
going on so what is it with the red halo? I can't find any color images
of the area. The POSS 2 plates do show it a bit brighter in red than
blue light but I see no sign of that odd halo I picked up. Could be
just dirt on a surface I suppose. I want to retake the color data this
year (taken September 30, 2011) and see if it reappears. So far the
weather hasn't cooperated.

The entire field seems to have a faint hint of galactic cirrus. I've
picked it up in other images in this area.

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

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