Main page
Astro page

The Minimum Aperture Catalogue (MAC)


The Minimum Aperture Catalogue is one of my amateur astronomy projects. The main aim was (and is) to determine the smallest telescope needed for a visual sighting of any deep sky object. The up-to-date version includes almost all objects in Uranometria 2000.0 and many other clusters, nebulosities and galaxies.

The catalogue is ordered by constellation. Within each constellation objects are listed in several subcatalogues, one table for each class of objects. The data includes one name, coordinates (J2000.0), magnitude, size, magnitude of cental star, number of stars or galaxies and dimensions if I've managed to find the data. In some cases (mainly open clusters) also my own estimates are included if the catalogue data is erroneous or missing. But that's mostly stuff you'll find somewhere else too. The most important parts are the short Notes for each object. The information in the Notes section depends on the type of the object. It do include the size of the smallest telescope used to view the object. This naturally includes only observations I know about! In many cases this means the value can be much too high.

There is one major drawback for most observers in all versions of the MAC catalogue: It do include only bright objects below declination -10; and none below -25;. For me this is quite reasonable as the local declination cut-off is -30;. History and Structure for more info.

The Catalogue was last updated 14.10.1997

Updated 14.11.2000