You can even set the limiting magnitude (i.e., how faint a star you want to have plotted). The authors include two handy buttons labeled "Rural" and "City," and the difference between the two is significant. You have many more stars in the rural view, but it takes considerably longer to plot.

You can choose which planets (as well as the Sun and Moon) to display. Solar system bodies are symbolized by small letters to distinguish them from stars. With the magnifier pointer, you can magnify the view of a small area of the chart, with or without lines connecting the stars in the constellations (and you can choose the magnification factor). See Figure E for an example.

FIGURE E

StarPilot's zoom function will magnify a chosen area from 2 to 10 times.

Using a third pointer to select an object will give you information about its name, what type of star or planet it is, and how far away it is. Other features let you find a star or constellation by name, and flip the chart for use at your telescope. StarPilot manages to successfully cram a lot of graphical information into a pretty small screen.

The fee for StarPilot is $30. StarPilot, Sun!, Moon!, and J-Moons! are also available as a package called StarPilot Plus for $44.95. The latest versions allow you to directly jump from StarPilot to the other three and back again without going to the Palm device's application menu.

Planetarium
Andreas Hofer wasn't content to take onedifferent tack with this application: he took a couple! One of the two views in Planetarium, shown in Figure F, offers a two-dimensional flat rectangular star chart of a part of the sky, with constellation lines and planets included at your option. This is similar to charts in typical astronomy textbooks, but is more interactive and dynamic.

FIGURE F

The horizontal line in this graphic of Planetarium's "S" view is the horizon (seems fitting somehow, right?). Stars are symbolized by dots of different sizes. The two unusual symbols stand for Saturn and Jupiter.

The other view format is unique to this program, as far as I know, and offers an interesting way to visualize where objects are in the current sky. In Figure G, Hofer draws a circle like a compass rose, and plots solar system objects along the circumference according to their compass directions. On a half-circle to the side, he plots the altitude (e.g., the distance in degrees above or below the horizon) of each object. For one object of your choice, he adds data in two kinds of celestial coordinate systems, plus the current distance from Earth. Finally, the current appearance of the Moon is shown, phase and all.

FIGURE G

Planetarium's "C" view plots the altitudes of solar-system objects on the left, and azimuths (compass directions) on the right.

There's a lot of information available in Planetarium, but it's displayed well with very little clutter. For instance, the program uses traditional celestial symbols for the planets rather than names, so that everything will fit. Fortunately, one of the help sections includes a chart of the symbols, helpful for those of us who are astronomers rather than astrologers (yes, there IS a difference!).