John Herschel discovered NGC 188 = h34 on 3 Nov 1831 and recorded a "Cl, vL, p Rich, 150-200 stars mag 10-18; more than fills the field." The Sky Catalogue 2000.0 gives a poor position of 00 44.0 +85 20.

200/250mm - 8" (8/24/84): large cluster, many faint stars, not rich, blank areas near center.

300/350mm - 13.1" (8/24/84): about 50 stars at 62x with several mag 7-9 stars in field, appears fully resolved.

400/500mm - 17.5" (12/26/00): At 100x, ~75 stars resolved within 10'-12', roundish group. The cluster is fairly rich but unconcentrated, with a noticeable void of stars near in the center and a somewhat ill-defined boundary. The stars appear to be layered; at least a dozen mag 12-13 stars are superimposed on a much richer carpet of mag 14-15 stars over unresolved haze. At 220x, some additional very faint stars are visible, bringing the total up to ~85 stars. Two mag 9.5-10 field stars (SAO 109 and 11) are just off the west edge and mag 8.7 SAO 149 is beyond the ENE border.

NGC 188 is one of the older known open clusters with an age of ~6.3 billion years and the closest to the north celestial pole.

Notes by Steve Gottlieb