ASTRO: Abell 194 A nearby galaxy cluster

I took this area of the sky several years ago but wasn't happy with the
color so gave it another try though the clouds did another number on it
the result is a bit better. Abell 194 is a galaxy cluster a bit under a
quarter of a billion light-years distant seen in the constellation of
Cetus so runs rather low in my sky which doesn't help. It is far larger
than my field of view being 3.75 degrees across. I aimed pretty much
for the center which put its two Arp Atlas entries a bit off center to
the upper left. Some of the text below is from my original attempt on
this area.

Arp 133 falls under Arp's very odd category of galaxies with nearby
fragments. It consists of two galaxies; NGC 541, the large cD/S0 galaxy
and the "fragment". They lie to the southwest of a pair of elliptical
galaxies that are Arp 308. The "fragment" is the very blue dwarf galaxy
to its northeast (upper left). This is not a fragment at all but a
dwarf galaxy undergoing extreme starburst star formation. It is known
as Minkowski's Object. NGC 541 is a radio galaxy with jets. One is
directed directly at Minkowski's Object and is credited with triggering
the starburst activity. Minkowski's Object has a different redshift but
this is more an indication of relative velocity than a real distance
difference. Arp 133 with its blue companion galaxy is almost identical
in appearance to the much nearer Arp 134 (M49 and its blue "fragment"
UGC 07636.)
http://www.spacebanter.com/attachmen...tid=2440&stc=1 Both
give me the impression that the "fragment" is a bug splat on the leading
edge of a "solid" galaxy that ran into it.

Arp had no knowledge of this at the time of his image. His image
carries a note that it was taken with a "Polaroid" filter. I assume he
means polarizing filter. How it was aligned it doesn't say. Arp's
comment on the image reads: "Central member of galaxy group associated
with 3C40." 3C40 is a strong radio source but not the radio source
involved with the starburst activity in Minkowski's Object. But it
does bring us to Arp 308.

Arp 308 is a pair of galaxies; NGC 545 and NGC 547 that are associated
with the radio source 3C40. That is NGC 547 is considered to be the
source of 3C40 along with the small galaxy CGG 385-129 to the west. Arp
put the NGC pair in his category of simply double galaxies. His simple
remark says: "Close ellipticals." which isn't very informative. NGC 545
to the north is listed as an SA0 galaxy while NGC 547 is E1 and a bright
cluster galaxy. Redshift puts it at 6 million light-years further from
us than NGC 545. However NED gives a D-Sigma distance determination
that is the same for both. Likely the difference in radial velocity is
due to relative motion rather than distance. The exact same D-Sigma
distance is found for NGC 541 (Arp 133) as well. Several sources say
the pair are not interacting. It does appear to me that NGC 547 lies in
front of NGC 545 based on the dark band between their cores which could
be caused by dust in NGC 547 blocking the light of NGC 545 behind it.

There's one asteroid in the image. It's information is noted in the
annotated image.

The annotated image includes the classification of each galaxy by NED.
That of the NGC project for NGC galaxies is listed after the NED
classification if different. When the same there is no second entry.
Note only NGC galaxies are classified by the NGC Project.

Arp's image of Arp 133 with an asteroid trail:
http://ned.ipac.caltech.edu/level5/A...ig_arp133.jpeg

Arp's image of Arp 308
http://ned.ipac.caltech.edu/level5/A...ig_arp308.jpeg

My image from November, 2011
http://www.spacebanter.com/attachmen...0&d=1322593005

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

Rick
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