Historic NGC/IC - Explanation

Dr. Wolfgang Steinicke

1 September 2022

The Historic NGC/IC is now merged in one file. It is a special version of the original NGC/IC, published by John Louis Emile Dreyer in 1888, 1895 and 1908 (listing alltogether 13226 objects):

New General Catalogue of Nebulae and Clusters of Stars; Mem. Roy. Astr, Soc. 49, 1-237 (1888)

Index Catalogue of Nebulae found in the Years 1888 to 1894; Mem. Roy. Astr, Soc. 51, 185-228 (1895)

Second Index Catalogue of Nebulae and Clusters of Stars Containing Objects found in the Years 1895 to 1907; Mem. Roy. Astr, Soc. 59, 105-198 (1908)

The Historic NGC/IC is a complete compilation about discoverers, dates, instruments, references and cross identifications in other historic catalogues. It is based on research by the author over the past 10 years, which has been published in August 2010 by CUP: Observing and Cataloguing Nebulae and Star Clusters - from Herschel to Dreyer's New General Catalogue (a german version is on the market since January 2009).

The sources for each object were traced in the literature (inspecting thousands of papers). Only in a few cases (35 NGC objects = 0.4%; 79 IC objects = 1.5%) a reference is missing. The NGC part ("Historic NGC") was first published on my website on January 6, 2006 and the IC part ("Historic IC") on April 23, 2008. There is a continuous update. As a new column the original NGC/IC descriptions were added (some typos and errors are corrected; compared to the descriptions previously published, they are fully reliable). Another new feature is the numbering of double or multiple entries (see explanation of columns below). The modern data of the NGC/IC objects come from the latest version of my Revised NGC/IC. See also the related files on the biographical data of the observers (with a large number of photos and object information) and the statistics of their discovery.

The Historic NGC/IC is available here (zipped xls-file). 

All data are copyright by the author and, if used in a publication or in other datasets, must be credited properly (please inform me in any case). Please inform the author about any errors found in the dataset.

Important note: The "Historically Corrected New General Catalogue" (HCNGC), first presented in April 2006 by the former NGC/IC Project member Bob Erdmann on the project website, is a mere copy of my "Historic NGC" of Jan. 2006 - including all its errors and uncorrected data. It is sad, that the necessary acknowledgment for using my data is not given there! The illegally presented "HCNGC" is incorrect and completely outdated and thus should not be used in any serious query! Hopefully it will soon be removed and substituted by my Historic NGC/IC data on the project website.

Columns in the Historic NGC/IC

N Catalogue: N = NGC, I = IC
NI Entry in original NGC and IC (NGC 1 ... NGC 7840; IC 1 ... IC 5386)
Discoverer Name of discoverer; see note below
Y, M, D Date of discovery; * or -1: entry in preceding column (Y, M) is only estimated; see also note below
Ap Aperture of telescope (inch)
Type of instrument: Rl = Reflector, Rr = Refractor; E = naked eye
Type of observation: v = visual, p = photographic, s = visual spectroscopy
Observer1 & 2
Other (independent) discoverers; later findings
RH ... DS
Position 2000.0 (as given in the Revised NGC/IC)
Revised visual magnitude (as given in the Revised NGC/IC)
Constellation (as given in the Revised NGC/IC)
Object type (as given in the Revised NGC/IC, but not as detailed)
Object status: 1 = galaxy, 2 = galactic nebula, 3 = planetary nebula, 4 = open cluster, 5 = globular cluster, 6 = part of nebula, 7 = NGC dublicate, 8 = IC dublicate, 9 = star(s), 10 = not found; see statistic table
Description Dreyer's original description as given in the NGC/IC (with a few corrections)
M Messier-Number
Class W. Herschel designation (class & number)
h J. Herschel number; 1...2306 = Slough catalogue; 2308...4021 = Cape catalogue
GC Number in J. Herschel's "General Catalogue" (1...5079), or Dreyer's supplement (5080...6251)
Other Other designations (e.g. Auwers, Dunlop, Lacaille); popular names (historic and modern)
ID1, ID2, ID3 Double identifications in NGC/IC
List Designation or number in lists given in the sources (primary S1, additionally S2)
R1, R2, R3, R4, R5 Source; see reference table
D1, D2, D3 Identification of multiple entries inside NGC or IC or between them. D1 = 2, 3 or 4: double, triple or quadruple; D2: nunning number of multiple entry (1...567); D3: number inside each multiple entry (1, 2, 3 or 4)

Note about discoverer and date: The information given in these columns relates to the discovery of the NGC/IC entry. This can differ from the discovery of the NGC/IC object! This is relevant in case of an identity (see colums ID1-ID3). For example: NGC 6 was found by L. Swift on 20.9.1885, but there is an identity with NGC 20, discovered by Mitchell on 18.9.1857.