Another night, another big galactic-sized system. I though I would take the cheap way out and do the Andromeda Galaxy, but fortunately I have a rather better set tonight. Two big galaxies for the price of one. Let's look at...IC 1166. One and two.
These are also S0-style systems, and both are substantially bigger than the Milky Way but individually smaller than IC 1101. IC 1166-1 (left) is 25% larger than our galaxy. The other, IC 1166-2, is just under twice the size. Together they make IC 1101 look like a piker, and it certainly looks like they will be together quite soon. In fact if you fly in between the rim of #1 and the dome of #2, you get stars from both galaxies mingling with each other. Utterly nuts!
Added (09.09.2011, 12:01)
I took a little time to look for some larger spirals of other types after all the S0's; large irregulars tend not to be photogenic.
So here is NGC 4727, just a bit over 100 Mpc away from Earth. It's the same type of galaxy that the Milky Way is (SBc), but it's twice as large as ours. A few years back a Type II supernova popped off around here at Magnitude 18, by far one of the more notable things about the place outside of its size.
Lots of bright blue systems along the disk. One of them even has a nice desert planet that isn't too hot, despite the system. I really wish I could find a Terra is an O0 system, or even O1/O2. Hell, I'd like to *find* an O0 or O1, the hottest ones I can find are O2 no matter where I look. If anyone has one they've tucked away, feel free to share.
And another thing (not to consciously reference the terrible sixth HG2G book that Irish fellow wrote recently): why aren't there many, if any, procedural O2 systems that are not binary? It seems like everywhere outside of the Orion Arm is at least a binary system, especially in other galaxies.