The double listing is not due to Dunlop, but to John Herschel, who reobserved all of Dunlop's objects (that is, the ones he could find). NGC 1854 refers to the brighter core of the stellar association, which was presumably observed by Dunlop (and by Herschel, in five separate observations of the region). NGC 1855 refers to a fainter outer "halo", which Herschel noticed on only one occasion. Since the two NGC numbers refer to different portions of the same object, they are in a sense identical, and are usually listed that way; but since NGC is a fainter outer region only noticed by Herschel, Herschel should probably receive credit for its discovery, even if it is still part of the same object. However, the present (first) iteration of this page only records the discoverers as listed in Wolfgang Steinicke's database; so any change in the presentation of the "discovery" will be made during the third or fourth iteration (when Dreyer's NGC/IC data is added).

The double listing is not due to Dunlop, but to John Herschel, who reobserved all of Dunlop's objects (that is, the ones he could find). NGC 1854 refers to the brighter core of the stellar association, which was presumably observed by Dunlop (and by Herschel, in five separate observations of the region). NGC 1855 refers to a fainter outer "halo", which Herschel noticed on only one occasion. Since the two NGC numbers refer to different portions of the same object, they are in a sense identical, and are usually listed that way; but since NGC is a fainter outer region only noticed by Herschel, Herschel should probably receive credit for its discovery, even if it is still part of the same object. However, the present (first) iteration of this page only records the discoverers as listed in Wolfgang Steinicke's database; so any change in the presentation of the "discovery" will be made during the third or fourth iteration (when Dreyer's NGC/IC data is added).