New General Catalogue

The New General Catalogue (NGC) is a well-known catalogue of deep sky objects in amateur astronomy. It contains 7,840 objects, known as the NGC objects. The NGC is one of the largest comprehensive catalogues, as it includes all types of deep space objects and is not confined to, for example, galaxies.

The catalogue was compiled in the 1880s by J. L. E. Dreyer using observations mostly from William Herschel and his son John, for total of 7,840 objects. Dreyer had already published an update to the Herschel's Catalogue of Nebulae, but a new update was turned down by the Royal Astronomical Society, who asked Dreyer to compile a New General Catalogue.

The NGC was later expanded with two Index Catalogues (IC I in 1896 & IC II in 1905), adding a further 5,326 objects. Most of these later discoveries had been made possible by the advent of photography.

Objects in the southern hemisphere sky are somewhat less thoroughly catalogued, but many were observed by John Herschel or James Dunlop. The NGC contained many errors, but a serious if not complete attempt to eliminate them has been undertaken by The NGC/IC Project www.ngcic.org, after partial attempts with the Revised New General Catalog (RNGC) by Sulentic and Tifft in 1973, and NGC2000.0 by Sinnott in 1988.

The NGC was published in the Memoirs of the Royal Astronomical Society as "A New General Catalogue of Nebulae and Clusters of Stars, being the Catalogue of the late Sir John F.W. Herschel, Bart., revised, corrected, and enlarged." (Dreyer J. L. E., 1888, Mem. R. Astron. Soc., 49, 1-237).

http://en.wikipedia.org/wiki/New_General_Catalogue