Explanatory Notes for BElist.txt and NGC2000.txt Boyd F. Edwards Department of Physics West Virginia University edwards at wvnvms.wvnet.edu May 20, 1996 BElist.txt is a tabulated list of 884 deep-sky objects. It includes: 1. 110 Messier objects; http://www.seds.org/messier/data1.html 2. 110 Caldwell objects; http://www.seds.org/messier/xtra/similar/caldwell.txt 3. 400 Herschel objects; http://www.seds.org/billa/herschel/h400.txt 4. 110 "Finest" NGC objects compiled by Alan Dyer, in Observers Handbook 1996, Ed. Roy L. Bishop, Royal Ast. Soc. Canada, Toronto Press, p. 217. 5. Essentially all objects with lengthy descriptions and pictures in Burnham's Celestial Handbook (Dover, New York, 1978). 6. Many objects discussed in Sky and Telescope columns over the last 8 years. For each object on BElist.txt, reference is made to other lists on which it appears, and specific reference is made to pictures and text des- cribing the object in the literature. This allows the potentially more interesting objects on the list to be identified by their larger number of references. It also allows for concurrent completion of several lists without duplication - there is considerable overlap between the lists! Furthermore, references to the literature allow for quick access of detailed information in Burnham's and other references. In BElist.txt, objects are sorted alphabetically by constellation, and are easy to sort by NGC number, by right ascension, etc., since the file is in 'spreadsheet' format, with tab characters separating its columns. Furthermore, the file NGC2000.txt contains the entire NGC and IC catalogs in this same format (13,226 objects in all), thereby allowing for straightforward deletion and insertion of objects of interest, and for subsequent sorting. The file NGC2000.txt is a spreadsheet version of the excellent updated NGC list edited by R. W. Sinnott; http://www.seds.org/billa/NGC2000_0.txt http://www.seds.org/billa/NGCintro.txt Both BElist.txt and NGC2000.txt are Macintosh text files created in Microsoft Excel 4.0 but saved in text format, to allow them to be read by spreadsheet programs on a variety of platforms. When rendered in 9 pt Times font in Microsoft Excel, all of the columns fit onto a single page in landscape mode (longways). The column headings are: SEEN NGC CON TYPE MAG SIZE DIST RA DEC COMMENTS REFERENCES The object TYPE codes are: OC Open Cluster GC Globular Cluster PN, Pl Planetary Nebula BN, Nb Bright Nebula (Diffuse) EN Emission Nebula (Diffuse) RN Reflection Nebula (Diffuse) C,N Cluster and Nebula (Diffuse) DN Dark Nebula G, Gx Galaxy SG Spiral Galaxy EG Elliptical Galaxy IG Irregular Galaxy LG Lenticular (S0) Galaxy SN Supernova Remnant A, dbl System of Binary Stars or Asterism B Milky Way Patch C Binary Star Qu Quasar The multiplicity of type codes stems from the variety of sources from which the data originated. Object magnitudes (MAG) and sizes (SIZE) vary substantially from list to list, largely because these characteristics of extended objects vary with the aperture of the telescope used to make the measurement; no attempt to identify a "correct" value has been made. A "p" following the magnitude indicates that the magnitude was measured photographically (see NGCintro.txt referenced above). Sizes are given in minutes of arc, except for some planetary nebulae, which are given in seconds of arc. Distances (DIST) are in light years, with the prefix k signifying X1000 and the prefix M signifying X1000000. Brief comments (COMMENTS) for each object are adapted from one of the above sources. (See NGCintro.txt for interpretation of the visual description codes in NGC2000.0.) The REFERENCES column identifies the lists on which the object appears and gives specific references to discussions and photographs of the object in the literature, as follows: 2/668 detailed discussion in Burnham's, Vol. 2, p. 668 a on Astronomical League's (AL) Herschel Club List of 400 objects b3/90 discussion in Backyard Astronomy Column in S & T, March 1990 (3/90) c on Caldwell List d2/89 discussion in Deep-Sky Wonders Column in S & T, February 89 e on personal list of showpiece objects o on 110 'Finest' NGC list from Observer's Handbook, p. 217 o' challenge object from Observer's Handbook, p. 220 n on Norton's early Herschel list, but not on AL Herschel list p120 picture in Peterson's Field Guide to Stars and Planets, p. 120 s4/91 discussed in Sky and Telescope article other than d or b, April 91 The list BElist.txt is not intended to be a definitive list in any sense; it likely omits some interesting objects and includes many that are quite difficult. Since it is the union of several well-known lists, though, it likely includes the major objects of interest in the heavens. Owing to the inclusion of objects discussed in several Sky and Telescope columns, it includes many objects of interest that are frequently overlooked. The list was compiled with my 6" dobsonian in mind, and I expect that most of the objects on the list should be visible through such a telescope on a clear, dark night, though some objects should prove to be quite challenging with that aperture, and others will be impossible. Guidance about the visibility of particular objects for various apertures is often found in the references. It would be interesting to cross reference these with Luginbuhl and Skiff's Observing Handbook and Catalogue of Deep-Sky Objects, a copy of which I would like to obtain soon. The list is intended to be an evolving personal master list that I can use to keep track of the objects I've seen to supplement my personal observing log. When I read about an object in a book or article, I like to be able to check back to see whether I've seen the object or not. This list allows me to do that. As is evident from the SEEN column, I've only barely begun the list myself. It will likely keep me busy for several years. I had intended to use Voyager II software for Macintosh to fill in the distance column, but lost enthusiasm. Basically, nebulae and open clusters typically reside at a few thousand light years, globulars lie at a few tens of thousands to hundreds of thousands of light years, and galaxies lie at tens to hundreds of millions of light years. The files BElist.txt and NGC2000.txt described above can be obtained in their original format (described above) via ftp from ftp://ftp.seds.org/incoming/ in a file called BE.zip. Hartmut Frommert has kindly rendered the file BElist.txt in an html format suitable for viewing with WWW browsers. Called BElistA.txt, this file is accessible via the same path used to access the present document; http://www.seds.org/messier/xtra/similar/BElistA.txt Many thanks to Claudio Veliz, Rich Neuschaefer, Anthony Beresford, Hartmut Frommert (Hartmut.Frommert at uni-konstanz.de), Lew Gramer (dedalus at latrade.com), Eric Greene (erg at america.net), Bill Arnett (billa at znet.com) and many others for their help and encouragement, and to the authors of these many lists. Special thanks to Hartmut for his willingness to include the list in his excellent SEDS Messier site. -Boyd Edwards