Based on a recessional velocity of 5910 km/sec, IC 1550 is about 260 million light years away. Given that and its apparent size of 0.55 by 0.55 arcmins, it is about 40 thousand light years in diameter.

Per Dreyer, IC 1554 (= D.S. 110, 1860 00 25 55, NPD 122 48) is "very faint, very small, extremely extended 170°, suddenly brighter middle". The position precesses to the one listed above, but there is nothing there, or anywhere near there. Steinicke lists the object as not found. Thomson states that the object almost universally designated as IC 1554 lies nearly a quarter degree away, which would be an "extremely unusual" error for Stewart to have made, and notes that the purported IC 1554 does not resemble Stewart's description (which has the nebula extended slightly east of south, while the "accepted" IC 1554 is extended well to the west of south). Corwin makes no mention of problems with the object, but per Thomson, agrees that the galaxy identified as IC 1554 is not the correct one. Since the three most knowledgeable authorities on the historical NGC/IC agree that the supposed IC 1554 is the wrong object, I cannot help but agree with their assessment. For that reason, the object generally referred to as IC 1554 is referred to on this site as PGC 2000.

Based on a recessional velocity of 1735 km/sec, PGC 2000 is about 75 million light years away. Given that and its apparent size of 1.4 by 0.8 arcmin, it is about 30 thousand light years across. The galaxy is listed (as the nonexistent IC 1554) in NED as being part of a pair with half-degree distant NGC 148, and also as a member of LGG 007, the NGC 134 group of galaxies, which includes NGC 115, 131, 148 and 150, IC 1555 and PGC 2044. Several of these are also listed as members of a group of galaxies in (or near) Sculptor with recessional velocities of about 1500 to 1800 km/sec (this is not "the" Sculptor Group, a close neighbor to our Local Group, with an average recessional velocity of less than 300 km/sec); so all LGG 007 group members are presumably members of the larger group.

Per Dreyer, IC 1555 (= Swift's list XII (#3), 1860 RA 00 27 41, NPD 120 46.2) is "most extremely faint, small, round, 2 stars in line to west". The position precesses to RA 00 34 36.4, Dec -29 59 51, about 3.6sE 1'12"N of the center of the galaxy, but there is nothing else nearby, so the identification seems certain. Based on a recessional velocity of 1570 km/sec, IC 1555 is about 70 million light years away, in good agreement with redshift-independent distance estimates of 65 to 85 million light years. Given that and its apparent size of 1.3 by 0.9 arcmin, it is about 25 thousand light years across. IC 1555 is listed as a member of LGG 007, the NGC 134 group of galaxies, which includes NGC 115, 131, 148 and 150, PGC 2000 (erroneously identified as IC 1554) and 2044. Several of these are also listed as members of a group of galaxies in (or near) Sculptor with recessional velocities of about 1500 to 1800 km/sec (this is not "the" Sculptor Group, a close neighbor to our Local Group, with an average recessional velocity of less than 300 km/sec); so all LGG 007 group members are presumably members of the larger group.