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ASSA Double Star Observing Program


Welcome to the Astronomical Society of Southern Africa’s Double Star Observing Program. The purpose of the Double Star Observing Program is to introduce observers to some of the finest double and multiple stars in the heavens. You don't need a large, expensive apochromatic refractor to view the objects on this list since a small refractor, Newtonian reflector, or Schmidt-Cassegrain will do just fine. This program is meant to allow you to enjoy a different aspect of our wonderful hobby, and not to test your equipment.

Double star observing can be very forgiving. You don't need the darkest skies, the clearest skies, or even a moonless night to observe many of these objects. Some can be observed from your backyard under moderate light pollution, some can be observed under less than transparent skies, and some can even be observed with the moon up. However, as usual in astronomy, the best results can be obtained under optimum conditions. The point is, always try for the best conditions, but if you don't have them, don't worry about it. You can still enjoy this program.


If you observe double stars and are a member of the Astronomical Society or one of its local centres’s, you may qualify for an ASSA Merit Certificate. Any telescope may be used, but one with an objective 60mm in diameter or larger is recommended. To record your observations, you may use the log sheet provided, or one with similar information.

Your observation records must include:

  • Name of the object
  • Date of the Observation
  • Time of the Observation
  • Description of object
  • Power used
  • Seeing conditions
  • Instrument used
  • Drawing of the double or multiple system.

Yes, I said a drawing of the double star. Now, before you panic, how hard is it to draw two dots in the box provided, with the size of the dot indicating magnitude, and the distance between the dots representing separation?

You must be a member of The Astronomical Society of South Africa to receive a Merit Certificate / Award.

The Log sheet is available in both Word and Adobe PDF format.

The Double Star Observing List contains 100 Double Stars which can be observed and measured. This list is for both Hemispheres. For more Double Stars please visit the “Washington Double Star Catalogue” at their website:

Please submit all your observation(s) and information to the ASSA Double Star Section Director.



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