The Revised New General Catalogue (RNGC) and companion Revised Index Catalogue (RIC) is a revision to the original New General Catalogue and Index Catalogues made by J. L. E. Dreyer. Some of the brightnesses of objects measured by Dreyer were not accurate or the description of the object was not accurate. Therefore they were revised. Most planetarium computer programs use the RNGC and the RIC as a source for their Deep sky object dataset.
