Wikipedia states this galaxy is the largest known in the universe, from 5-6 million light years. A 1991 paper by Uson, Boughn, & Kuhn (ApJ, 369, 46) gives a slightly smaller, though still extremely large diameter of 4 million light years.

Edward Swift, the son of Lewis Swift, discovered IC 1101 = Sw. IX-47 on 19 Jun 1890 at the age of 19. Lewis noted that he and Edward disagreed on the description after the telescope was moved, and as a result no description is given in Swift's 9th discovery list. In his survey of NGC/IC objects around 1900, Herbert Howe found it to be "extremely faint and very small. A star of mag 13 follows 1.5 seconds...and another precedes 2 seconds, a little north." UGC does not label their entry (UGC 9752) as IC 1101.

This is a super-giant cD in the center of AGC 2029 at a distance of 1.07 billion light years (slightly larger redshift than AGC 2065!). IC 1101 is certainly one of the most distant galaxies discovered visually (and possibly the most distant)!

400/500mm - 18" (6/30/11): this supergiant cD galaxy is the central galaxy in AGC 2029 (z = .078 at 1.0 billion light years!). At 280x, it appeared very faint, very small, slightly elongated ~N-S, ~15"x10". Visible continuously with averted vision. The galaxy is centered within a 9-member circlet of 12th- to 14th-magnitude stars and squeezed between a mag 14.7 star 27" E and a mag 15-15.5 star 47" WNW (just slightly south of a line connecting these stars). No other members of the cluster were seen. I also viewed IC 1101 at a similar magnification in a 24" f/3.3 and logged it as "faint, very small, oval 3:2 N-S, ~20"x14". Could just hold steadily with direct vision."

Notes by Steve Gottlieb