James Dunlop's Catalog of Deepsky Objects

In the years 1823-1827, James Dunlop (1795-1848) observed the southern skies from the Brisbane observatory at Paramatta, New South Wales, Australia. He compiled several catalogs, among them the Brisbane Catalogue of over 7000 southern stars, and A Catalogue of Nebulae and Clusters of Stars in the Southern Hemisphere observed in New South Wales of 629 entries for deepsky objects [Dunlop (1828)]. However, many of these objects are badly described, so that John Herschel could only verify 211 of them. New research, led by Glen Cozens, brought up a number of further "real" objects, so that actually roughly over 300 (or about 50 %) seem to belong to "real" deepsky objects. The other half is asterisms and multiple stars which Dunlop's comparatively small instruments (a 9-feet FL, 9-inch aperture reflector with speculum metal mirror, perhaps equivalent to about a modern 6-inch reflector) didn't resolve.

The most spectacular original discovery of Dunlop is perhaps that of peculiar radio galaxy NGC 5128 in Centaurus (also called Centaurus A), his Dunlop 482. Also included in his original discoveries are Sculptor Group galaxies NGC 55 (Dun 507), 300 (Dun 530), and 7793 (Dun 608), and a considerable number of further southern galaxies, open and globular clusters, diffuse nebulae, and 4 planetary nebulae (NGC 2818=Dun 564, NGC 5189=Dun 252, NGC 5882=Dun 447, and NGC 6563=Dun 606). Dunlop has included 6 Messier objects in his list: M54=Dun 624, M55=Dun 620, M62=Dun 627, M69=Dun 613, M70=Dun 614, and M83=Dun 628.

This endeavor was the second major effort of a deepsky object survey of the southern skies, after Lacaille's list of 42, of 1751-1752.

Here we offer the following options related to Dunlop's catalogue online:

Dunlop 100: 100 highlights from the Dunlop catalogue. By Glen Cozens. Also available as ascii file. Also published in Sky & Telescope [Cozens (2001)]

References

James Dunlop, 1828. A Catalogue of Nebulae and Clusters of Stars in the Southern Hemisphere observed in New South Wales. Philosophical Transactions of the Royal Society, Vol. 118, p. 113-151
Glen Cozens and Graeme L. White, 2001. James Dunlop: Messier of the Southern Sky. Sky & Telescope, Vol. 101, No. 6 (June 2001), p. 112-116.

Other Deep Sky catalogs suitable for the amateur

History of the Discovery of the Deepsky Objects

Hartmut Frommert (spider@seds.org).
Christine Kronberg (smil@lrz.uni-muenchen.de)

Last Modification: 8 May 2001