Rick,

very good detail for such a low objects. Tried M5 last night and didn't get
sharp images even though seeing was quite good some 20 degrees higher.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
ster.com...
Arp 123 is in the Arp class: "Elliptical or elliptical like galaxies;
close to and perturbing spirals". In this case the spiral is NGC 1888
and the elliptical is NGC 1889. At first look there doesn't appear to
be any distortion. Usually we expect to see the distortion on the side
of the companion but that doesn't have to be the case. Here it is on
the opposite side and takes the form of a large, faint blue halo of new
massive blue stars. I looked at several papers on this pair but none
were concerned with how the interaction would only throw out mostly new
hot blue stars leaving the old population of stars mostly unchanged.
Was there a lot of gas in this area and the interaction triggered the
star formation? If so why aren't they in clusters? There's no sign of
dust, just the stars. I found it odd that no one was much interested in
this. Maybe it isn't a puzzle to them but it sure is to me. The pair
are about 115 million light years away.

The papers did have this to say: "Liu & Kennicutt (1995) state NGC 1888
to be a spiral of the type Sa or Sb with dominant old stellar population
and only weak line emission." Yet another paper says; "With NGC 1888,
forms = Arp 123 an interacting pair at 0.3 arcmin, consisting of a large
Sc with faint outer arms and a small E0 in contact." I doubt that
means actual contact, just apparent contact. I see no evidence of an
actual collision.

The other galaxy of any size is toward the upper left corner, northeast
of Arp 123. It is MCG -02-14-015 also at 115 million light years. With
the same distance it must also be a very close neighbor to Arp 123. NED
classes it as S0 which seems strange. Those are usually white to
yellow, often elongated spindle shaped galaxies with little to no dust
or gas and consisting of old stars indicating star formation ceased
billions of years ago. Yet this galaxy has the typical blue arms of an
edge on spiral. On the other hand it has no dust lane as you'd expect
with an S0 galaxy. One paper I found says it is "an anonymous Sc
galaxy" in a paper on Arp 123. Only a very few other galaxies have
been cataloged in this image. They are strong emitters of IR radiation
and thus in the 2MASS catalog if IR sources. No visual or red shift
data is available on them however.

This galaxy pair is located in Lepus the rabbit, near the border with
Orion. Down that low my seeing is never very good though it was
somewhat better than average for its declination. Still, it's not what
I would like.
Arp's image is at:
http://nedwww.ipac.caltech.edu/level...ig_arp123.jpeg
It appears his seeing wasn't much better than mine. Though the poor
dynamic range of film caused him to lose a lot of detail in the galaxies
while exposing long enough to pick up the blue halo. Today's digital
sensors don't have this limitation. Though I again put a bright star on
the edge of the chip. Difficult if you try but apparently very easy to
do if you don't.

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

Rick
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Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".