Above:   The 2011 July 19  Occultation of the magnitude 6.7  star HIP 112420 by  binary Asteroid 90 Antiope.  The combined result of timing observations by 56 observing stations in North America by mostly amateur observers, organised by the International Occultation Timing Association (IOTA).  This is the best information ever obtained on this asteroid system.  See the Wikipedia article on 90 Antiope.




Item of sentimental personal technical interest:  Radio VNG


Resources for Observers:


Local Documents: