New General Catalogue - Original Catalogue

Original Catalogue

The original New General Catalogue was compiled during the 1880s by John Louis Emil Dreyer using observations from William Herschel and his son John, among others. Dreyer had already published a supplement to Herschel's General Catalogue of Nebulae and Clusters (GC), containing about 1,000 new objects. In 1886, he suggested building a second supplement to the General Catalogue, but the Royal Astronomical Society asked Dreyer to compile a new version instead. This led to the publication of the New General Catalogue in the Memoirs of the Royal Astronomical Society in 1888.

Assembling the NGC was a challenge, as Dreyer had to deal with many contradicting and unclear reports, made with a variety of telescopes with apertures ranging from 2 to 72 inches. While he did check some himself, the sheer number of objects meant Dreyer had to accept them as published for the purpose of his compilation. Dreyer was a careful transcriber and made few errors himself, but the catalogue nonetheless contained several errors (mostly relating to position and descriptions). He was very thorough in his referencing, which allowed future astronomers to review the original references and published corrections to the original NGC.

The NGC was later expanded with two Index Catalogues, adding a further 5,386 objects. Most of these later discoveries had been made possible by photography.