Very good image of this pair (that I wasn't aware of before).
Have you changed your image processing procedure recently? It seems to me
that you are showing more noise in the fainter parts than you used to.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
ster.com...
Arp 304 consists of two galaxies NGC 1241 and NGC 1242, right to left
and a double star to the southeast, NGC 1243. The two galaxies were
first seen by William Herschel. John Herschel, unable to see 1242
recorded the double star. Dreyer saw all three but recorded the double
star as a nebula. It seems odd that even with a 72" scope (speculum
mirror I assume) he couldn't recognize 2 14th magnitude stars 12" apart.
The NGC is full of such mistakes, some single stars.

The pair is about 175 to 178 million light years distant in the
constellation of Eridanus. Arp put them in his catalog under double
galaxies with filaments. I suppose that is the northward arm of NGC
1241. While red shift puts them at about the same distance there's some
question about whether they are interacting or not. One note at NED
says no, another yes and another wanted more data. NED classes NGC 1241
as SB(rs)b Sy2, NGC 1242 as SB(rs)c:. NGC 1241 does have that odd arm
and NGC 1242 seems odd with that very blue northern arm and one heavy
arm. So I vote for the interaction being possible. Still there are no
real plumes which is likely why others say no interaction.

The field is out of the Sloan Survey coverage. Only one other galaxy in
my field has a known red shift. To find it look well east (left) and a
bit south (down) of Arp 304. It is the largest red round galaxy.
Further east is a close rather bright double star with a blue galaxy
above it. The red one is 2MASX J03121399-0858394 at 1.3 billion light
years. The blue one is APMUKS(BJ) B030959.78-090917.2. Other than it
being magnitude 18.15 there's no data on it or any other galaxy in the
image.

But there is one asteroid 2005 LZ45 at magnitude 19.8 shows up as a
short streak angling slightly upward west of the bottom end of NGC 1241.
It is at the edge of the 150% crop image above a slightly orange star
that's the first up from the bottom right corner of the cropped image.

This is my last November image (maybe not -- I just found another lost
on the hard drive but with weak maybe unusable green data). Now I can
move to December. December was mostly cloudy. Only one clear night and
it lasted only half the night so only 3 images for that month (well 4,
as I found a lost one there too with weak color data that I may be able
to salvage). Soon I'll be processing 2010 images!

Arp's image
http://nedwww.ipac.caltech.edu/level...ig_arp304.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

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