Occult 4.0

Occult is a continuation of incremental improvements to the Occult software.
Main features:
- A tool for comparing star catalogues so that the accuracy of asteroidal occultation predictions can be better assessed;
- The incorporation of shape models into asteroidal occultation reductions;
- Retrieval of AAVSO light curves for stars, light curve data for asteroids, and star diameter measurements
- Implementation of lunar profiles derived from the Kaguya satellite altimeter measurements - effectively consigning the Watts charts to history.
- A major overhaul of double star issues.

This included download capabilities for the Washington Double Star catalog, the 4th Interferometric Catalog, and the Index catalogue of variable stars maintained by the AAVSO. The double star files for lunar occultations were completely revised - with a 100% increase in the number of pairs.
- A large number of changes resulting from an invitation to users to suggest improvements.