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The history of the catalogue

The first version of what was to come the MAC saw starlight in 1990. The most important revisions have been the inclusion Lynga clusters in 1993, and galaxies from MCG, UGC and CGCG among others in 1994. The latest major cataloguequake affected the planetary nebulae tables as the Strasbourg-ESO catalogue was included as a whole.

The -25° declination limit was chosen while I lived in Jyväskylä, a small city in central Finland, at latitude 62,5° N. I've been thinking about a southern sky extension but it's a low priority thing for me. However, if someone is interested in compiling the -10 - -90 degrees constellations I'll help in all possible (and maybe some other) ways.

The structure of the data tables clearly shows the original purpose of the catalogue: to serve as a night-time field list and reference. Originally each constellation entry covered one A4-size sheet (both sides) but the latest version has expanded quite a lot. This explains the omission of some very faint (mag. 18 or fainter) planetaries and open clusters.

My own version is in Finnish and some single words might have slipped past the translating process. If you locate any mysterious terms such as Kaila or sumu please drop me a note.


Structure

As the lenght of the data array is limited by technical reasons the information is in many case coded and many abbreviations are used.

First three spaces This space is used for pointing to references. An * sign refers to Skiff-Luginbuhl: Observing Handbook and Catalogue of Deep Sky Objects, Cambridge University Press.
Numbers between 2 and 7.These refer to the Webb Society Deep-Sky Observer's Handbooks volume 2-7.
U U stands for Uranometria 2000.0, a high-quality sky atlas by Tirion, Rappaport and Lovi. The two-volume book is published by Willmann-Bell, Inc. The number refers to the page number(s). If the page number is surrounded by parentheses () the object is not plotted in U2000. Usually 2 of max. four possible pages are mentioned.
Class,Mag,Size These are self-evident.
Mag*This abbreviation is short-hand for central star magnitude.
*The asterisk denotes numer of stars in open clusters.

Abbreviations

st Magnitude of stars, stellar
Br Bright(est star)
* Star
dbl Double
PA Position angle
gr Group
comp Companion
P w Paired with
SBr Surface Brightness
§ Galaxy
EDL Equatorial dust lane
HII Emission region
O/Hß The relative strenght of the O-III (500.7 nm) and Hß lines

Example

   name        U         class    mag   size   *     ra (2000.0) de notes
-----------------------------------------------------------------------------------
*3 NGC 6756    251       I 2 m    10.6  4'     40    19 08.7 +04 41 st11...   vF 6"

NGC 6756 is an open cluster in Aquila. It is mentioned in the Observing Handbook and in Observer's Handbook volume 3. It is plotted on page 251 in Uranometria. The class stands for: Compressed, moderate brightness range, moderately rich. It includes forty stars. The notes tell us that the stars are magnitude 11 and fainter. The cluster is very faint with a 6-inch telescope.

The following filtering rules have been used:

Open and Globular clusters and all nebulosities All known (to me) higher than dec. -25°. Some very faint open clusters (Brightest stars fainter than 18m) excluded.
Galaxies The limiting magnitude for galaxies ranges from 15.0m (v) in small constellations like Equuleus to 14.0m (v) in the Coma-Virgo area. Below declination -10° the cut-off is at 12.0m (v).
Galaxy clusters All Abell clusters with distance class 3 or less. None below -10°
In many cases objets of special interest like Maffei I & II and some quasars are included even if they don't meet the 'official' criteria.

Updated 14.11.2000