Historic IC - Explanation

Dr. Wolfgang Steinicke

January 23, 2010

The Historic IC is a special version of the IC, based on research on the observers and their published observations done by the author over the past years. The sources for each object were traced in the literature (inspecting thousands of papers). Only in a few cases (78 objects = 1.5%) a reference could not be found (most of these objects were privately communicated to Dreyer by Barnard). This is, for the first time, a complete compilation about discoverers, dates, instruments, references, and cross identification in other historic catalogues. The Historic IC was first published on April 23, 2008 and is subject to continuous update.

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. Click here to download the "Historic IC" (zipped xls-File). The modern data of the IC objects comes from my 2009 version of the Revised IC. All information presented here is part of my scientific research. My upcoming book "Obervation and Cataloguing Nebulae and Star Clusters - from Herschel to Dreyer's New General Catalogue" will contain some information about the IC too. I will be published in mid-2010 by Cambridge University Press (a german version is on the market since January 2009).

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).

 

Columns in the Historic IC

Column
Explanation
IC Entry in original IC
Discoverer Name of discoverer
Y, M, D Date of discovery; * or -1: entry in preceding column (Y, M) is only estimated
Ap Aperture of telescope (inch)
I
Type of instrument: Rl = Reflector, Rr = Refractor; E = naked eye
T
Type of observation: v = visual, p = photographic, s = visual spectroscopy
Observer1 & 2
Other (independent) discoverers; later findings
Rekt, Decl
Position 2000.0 (as given in the Revised NGC)
Vmag
Visual magnitude (as given in the Revised NGC - note that its revised magnitude system being not yet applied here)
Con
Constellation (as given in the Revised NGC)
Type
Object type (as given in the Revised NGC, but only roughly specified)
S
Status of object (as given in the Revised NGC); see statistic table
List Designation or number in lists given in the source
ID1, ID2, ID3 Double identifications in NGC/IC
Ref Source; see reference table