XEphem 3.5 - an interactive astronomical ephemeris for X
xephem [-prfb] [-install {yes|no|guess}] [-resfile <resourcefile>]
XEphem is an interactive astronomical ephemeris program for X Windows systems. It provides many graphical views as well as quantitative heliocentric, geocentric and topocentric information for Earth satellites, solar system and celestial objects.
XEphem contains extensive context-sensitive on-line help. Virtually none of that help is duplicated here so go ahead and run XEphem to learn more.
The Main window of XEphem provides control and display of three basic services: observing circumstances, looping, and access to additional tools and displays. Observing circumstances includes location, date, time and atmospheric conditions (used for the refraction model). Looping refers to the ability to set up XEphem so that it automatically increments time at a desired step size and rate. Additional displays provide all of the graphical and quantitative information available, and always refer to the circumstances defined in the main menu. Tools provide access to plotting, searching, AAVSO, Seti@Home and more.
-prfb displays all the built-in default resources, then exits.
File
This menu controls basic operation, including exiting. When XEphem is first started it may beep. This means a message has been put in the System log dialog, which can be displayed from this menu. Other chores here include setting up network access; displaying a simple progress meter; controlling time and location information remotely, and keyboard accelerators for time stepping.
View
This menu offers several graphical displays if the Earth, Moon and several planets; a user configurable table; and Sky and Solar System views.
Tools
This menu gives access to tools which can plot any XEphem data items; save any data items to text files for easy export to other programs; enter an arbitrary function to evaluate and solve using any XEphem data items; access AAVSO online; monitor your Seti@Home client; show the Night at a glance; find close pairs of objects; and convert among various astonomical coordinate systems.
Data
This menu gives control over which objects XEphem will work with. Objects may be created on the fly, read from catalog files, downloaded from the Internet, deleted or searched. A special category of objects known as Field Stars may be configured, which are very large catalogs of objects whose access has been optimized. Up to three User objects may be assigned for especially easy access in several other places throughout XEphem.
Preferences
This menu offers several configuration choices. These will effect the overall appearance or behavior of XEphem. These choices, as well as fonts and colors, can be changed at runtime and saved to disk to become the new defaults.
Help
This menu offers overall information about XEphem; context sensitive help; several worked examples; references; version number and the Copyright statement.
XEphem initial conditions are defined using a resource file. By default the file is named XEphem located in a directory also called XEphem in your $HOME directory. You should never find the need to edit this by hand because XEphem will manage it when you Save settings.
Elwood Downey, email ecdowney@ClearSkyInstitute.com.
The latest information about XEphem is maintained at http://www.clearskyinstitute.com/xephem
The online Help entry on Credits lists many of the references, individuals and organizations which have contributed to XEphem.