The star map is an interactive plot of the current sky. Only objects currently above the horizon are shown, and these include the sun, moon, planets and a collection of the brightest stars. Equatorial lines are drawn, as well as the ecliptic and the boundary of the circumpolar region.
Any object plotted on the star map can be selected with the mouse, thus changing the current target of the telescope. RA/Decl coordinates may be entered using the Equatorial Coordinates dialog (similar to the Stonyhurst dialog, and obtained using the same top toolbar button). As with Stonyhurst coordinates, equatorial coordinates are stored in a list, and drawn on the star map as green crosses.
Stored equatorial coordinates may be selected with the left mouse button. The Next and Previous buttons allow you to move through the list, while the Delete button removes unwanted entries. Interconnecting lines can be drawn using the toolbar button.
At the bottom of the star map is an information area displaying the current equatorial coordinates as well as the name of the target and its constellation, if relevant.
It is possible to view the star map centered either on the zenith (default), or on the current target. The toolbar button toggles between each mode. Other toolbar buttons enable you to zoom in or out of the star map. As you zoom in, more star names will be revealed. These labels, and those for solar system objects, can be hidden using the toolbar button. The solar system objects themselves may also be removed using the relevant toolbar button.
The current position of the telescope is depicted as a line projected from the zenith. When tracking a target, this line is coloured green and extends from the zenith to the target. When not near its target, the line is drawn in red. The angle of the line represents azimuth and the length of the line represents elevation (when pointing to the zenith, the line has zero length, when at the horizon, is has maximum length).
![\includegraphics[width=0.6\textwidth]{figs/star_map.ps}](img4.png)