Historically-aware NGC/IC Positions and Notes


Here are current versions of my NGC/IC position and notes files. I have finished my main sweep through the catalogues, checking identifications and finding accurate positions from modern sources. As always, I update these files at irregular intervals. Check back occasionally for updates.

Latest updates:

What's new:

What's here:

This current file layout still carries a hint of historical baggage. I started the project three decades ago on computers with small and slow RAM and hard drives, so working with short files and 80-character lines was not just more efficient, but even necessary. I also worked in the equinox B1950.0 as that was the reference equinox for virtually all of my sources. In March of 2014, I finally switched to J2000.0, and now work on all 7840 NGC objects in a single file, and all 5386 IC objects in another. The 80-character line limit has been broken, too, at least in the position files. Aside from that, the format remains the same as it has been for the past 30 years.

If you want everything, and most people will, just download the *.all and *intro.html files. You'll also want at least one set of the mean position files, too, probably the J2000.0 set (ic2000.pos and ngc2000.pos), though the B1950.0 set may still be of some historical interest for comparing with the old catalogues I started working with in the early '60s. See the NGC/IC positions introductory file for more information.

All the files are 7-bit ASCII, by the way, with UNIX line-endings. I work now on a Macintosh running OS X (version 10.11.6, "El Capitan"). This gives me access to almost all of my old UNIX tools as well as the GCC Fortran compiler (currently version 6.1.0) for building the tools and programs I use to manipulate the data.

Creative Commons License
NGC/IC Positions and Notes by Harold G. Corwin, Jr. is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

This means that you are welcomed to use the Positions and Notes in any way you like (and you may correct any mistakes!), but please do acknowledge their origin. And if you find mistakes, please do let me know so that I can fix them, too.


Data and Images

Scattered throughout the J2000.0 base files and the notes files are data and cross-identifications for the NGC/IC objects. Unlike the data given in the various catalogues I've authored and co-authored over the years, these data are neither complete nor homogeneous. I shall get to this eventually.

In the meantime, if you need data for the NGC and IC objects, you will want to consult either

Note that the second of these lists may contain some data from the first inadvertently used without attribution. While Wolfgang is understandably upset about this, his claim of "illegal" use of his data is unwarranted. His comment about the outdated nature of the HCNGC file is, however, quite accurate, so I suggest using Wolfgang's much more recent files if you need data beyond what I present here. Note that a few of Wolfgang's identifications are different from mine. Compare the positions for an object to be sure that it really is the same one in each list. If they are different, please read my notes for my interpretation of the problem.

Finally, I am pleased to call your attention to Courtney Seligman's Celestial Atlas pages featuring images and notes for many celestial objects, including NGC and IC objects. In particular, many of the images -- some processed by Courtney himself -- are not only beautifully spectacular, but demonstrate the essential characteristics of the objects very well. Courtney is also tracing the history of every object; this is a welcomed and independent check on the work that those of us involved in the NGC/IC Project have done over the past decades.

Latest update, this file: 25 October 2016.