William Herschel discovered NGC 4567 = H IV-8 = h1358 = h1363 on 15 Mar 1784 (sweep 174) and recorded a "double nebula [with NGC 4568], or two p. considerable nebula apparently running into one another. The foregoing nebula [NGC 4564] may be taken into the field of view these two." Caroline's reduced position is ~6' southeast of the Siamese Twins.

Because of his father's poor position, John Herschel recorded the pair as a Nova (h1358 and 1359) at the correct position. He also made an observation with a poor position (h1363) that he associated with IV-8 and IV-9. The error was noted by d'Arrest in a 1863 paper.

The nickname "Siamese Twins" was coined by Leland S. Copeland and mentioned in his Feb. 1955 article "Adventuring in the Virgo Cloud".

200/250mm - 8" (4/16/83): faint, moderately large, appears as a double nebula at moderately large to high power.

300/350mm - 13" (4/16/83): fairly faint, elongated E-W. NGC 4568 is attached at the NE end.

400/500mm - 17.5" (4/25/87): northern member of a double system with NGC 4568. Moderately bright, fairly small, elongated 3:2 ~E-W. Slightly smaller than NGC 4568 attached at the east end but NGC 4567 has a slightly higher surface brightness.

Notes by Steve Gottlieb