ASTRO: IC 148 with NGC 660

IC 148 is a rather small blue, warped, disk galaxy in Pisces only 22
minutes of arc from the far more famous polar ring galaxy NGC 660. Just
too far for me to put them in the same FOV. They do have similar
redshift so are likely related and maybe even interacting. It may be
the cause of the warping of this galaxy. The distance to it is rather
uncertain. Even APOD won't try to pin that down for NGC 660 saying only
that it is over 20 million light-years from us. Redshift puts IC 148 at
22 million light-years while a single Tully Fisher estate says 35
million light-years. I tend to favor the larger value mainly due to its
angular size. If the 22 million light-year figure is used the galaxy is
only 22,400 light-years across. That seems small to me. The larger
distance makes it 35,600 light-years across, a more reasonable size. If
its angular separation from NGC 660 is a good indicator of their real
separation, that is they really are at the same distance from us, then
they are only 139 million light-years to 221 million light-years apart.
That's quite close. This, of course is the minimum distance between
them, the actual distance could be much greater since neither has a good
distance estimate.

NED classifies it in one place as Sc(f) and Im another. The latter
could be consistent with the smaller size and nearer distance while the
former gives it about the same size as M33 which fits its classification
better. In case you are wondering the (f) is from the Yerkes
classification system and means it has prominent F type stars. This
helps explain its rather blue color.

The annotated image shows a surprising number of quasars and quasar
candidates (labeled UvES in the annotated image). The one asteroid is
identified in the annotated image.

After writing the above I checked my image of NGC 660 taken in 2009
using generation 1 filters rather than generation 2 used for the IC 148
image. There was a small amount of overlap. My processing methods have
changed greatly since 2009 so it is processed much differently. Rather
than take the time to reprocess the 2009 image I did a quick rework to
sort of match the two into one large 2705x2464 mosaic at 1" per pixel.
Due to the small overlap of only stars the processing differences aren't
very noticeable. It does show the relationship between these two
galaxies. To do it right I need to retake NGC 660 with today's optical
train (even that has changed slightly) and process them the same. I
don't see that happening however. Thank goodness for RegiStar that
managed to match the two with only a very small overlap between the two
and slightly different image scales and distortions at the edges where
they meet.

Data for the IC 148 image:
14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME
Data for the NGC 660 image is the same but for some reason the blue
channel used three 10 minute images rather than 2 used for the other
color channels.

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

Mighty image Rick.
I like the colour contrast with IC 148 being much more blue than NGC 660.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

IC 148 is a rather small blue, warped, disk galaxy in Pisces only 22
minutes of arc from the far more famous polar ring galaxy NGC 660. Just
too far for me to put them in the same FOV. They do have similar
redshift so are likely related and maybe even interacting. It may be
the cause of the warping of this galaxy. The distance to it is rather
uncertain. Even APOD won't try to pin that down for NGC 660 saying only
that it is over 20 million light-years from us. Redshift puts IC 148 at
22 million light-years while a single Tully Fisher estate says 35
million light-years. I tend to favor the larger value mainly due to its
angular size. If the 22 million light-year figure is used the galaxy is
only 22,400 light-years across. That seems small to me. The larger
distance makes it 35,600 light-years across, a more reasonable size. If
its angular separation from NGC 660 is a good indicator of their real
separation, that is they really are at the same distance from us, then
they are only 139 million light-years to 221 million light-years apart.
That's quite close. This, of course is the minimum distance between
them, the actual distance could be much greater since neither has a good
distance estimate.

NED classifies it in one place as Sc(f) and Im another. The latter
could be consistent with the smaller size and nearer distance while the
former gives it about the same size as M33 which fits its classification
better. In case you are wondering the (f) is from the Yerkes
classification system and means it has prominent F type stars. This
helps explain its rather blue color.

The annotated image shows a surprising number of quasars and quasar
candidates (labeled UvES in the annotated image). The one asteroid is
identified in the annotated image.

After writing the above I checked my image of NGC 660 taken in 2009
using generation 1 filters rather than generation 2 used for the IC 148
image. There was a small amount of overlap. My processing methods have
changed greatly since 2009 so it is processed much differently. Rather
than take the time to reprocess the 2009 image I did a quick rework to
sort of match the two into one large 2705x2464 mosaic at 1" per pixel.
Due to the small overlap of only stars the processing differences aren't
very noticeable. It does show the relationship between these two
galaxies. To do it right I need to retake NGC 660 with today's optical
train (even that has changed slightly) and process them the same. I
don't see that happening however. Thank goodness for RegiStar that
managed to match the two with only a very small overlap between the two
and slightly different image scales and distortions at the edges where
they meet.

Data for the IC 148 image:
14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME
Data for the NGC 660 image is the same but for some reason the blue
channel used three 10 minute images rather than 2 used for the other
color channels.

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