Virtual Sky Watching

Abstract

As soon as personal computers were invented it was only natural that the digital equivalent of the planisphere would be created. From those early days of computing, sky simulations have been probably the biggest selling of all astronomical software. No astronomer worth his salt would be without one. All these programs will chart the sky for any date and place on Earth, some even as seen from other planets, although just how useful that would be is a moot point. The number of stars depends on the database included which can vary with versions. The most basic will have the Bright Star Catalogue which has over 9,000 stars down to magnitude 6.5. Next level up is the Smithsonian Astrophysical Observatory (SAO) Catalogue with 250,000 stars to around magnitude 8. Some programs include the Hubble Guide Star Catalogue with 15 million stars to magnitude 15 — enough for most people!