JSkyCalc

Skycalc expedites the "time-and-the-sky" calculations needed by observational astronomers. The newest version, JSkyCalc, features: *Re-written in pure Java to run on all major platforms, including Mac OS-X, Linux, and Windows *Can be launched from a web browser (requires Java Runtime Environment 1.5+, java enabled browser). *Modern, intuitive graphical user interface *Vivid planetarium-style sky display *Can read user-supplied object lists (Requires local installation) *You can add your favorite observatories (Requires local installation) *Quantitative estimates of moonlight and twilight Interference *Tabulation of Hourly airmass through the night, with warning colors that Flag potential interference *Sunrise, sunset, twilight, moonrise, and moonset times *Online manual included in the program. *New in version 1.1: Airmass-vs.-time graph for multiple objects. *New in version 1.2: Stars rendered in color; several other minor refinements. *Many more features too numerous to list.