Free astronomy software for linux

KAstrHorloge is an astronomy software for Linux & KDE.
KAstrHorloge is provided with a 10000 stars database. For any of these stars or planets, the software can compute its position in the sky of your observation site. It displays the object location both in a map and in terms of coordinates (alpha and delta)
For each star or planet, you can add your own comments (for example, some physical data, or observation comments) and even a CCD image of the object !
All functions of KAstrHorloge are intuitive and easily accessible, so you can use this software without reading the doc !
Good observations !
Enhancements:
- Added a dialog to choose the geographic location
- Used libAstronomy and libnova for calculations

SkyDome project is a tool to demonstrate the location of stars, planets, constellations, and the Milky Way during Earths rotation.
Besides the optical view, various other star maps are incorporated from satellites like COBE, EGRET, and IUE, making the multi-wavelength Milky Way visible to the user.
Enhancements:
- This release includes visualisation of radio sources.
- It uses IFS to plot radio astronomy WAV files on the skymap.

SLgtk package binds the GIMP Toolkit, also known as Gtk, to the S-Lang scripting language. This application was created with the SLIRP code generator, and provides an importable module which makes most of Gtk and its constituent libraries callable directly from S-Lang scripts.
With SLgtk the S-Lang programmer now has access to a powerful, cross-platform widget set for creating sophisticated graphical user interfaces (GUIs). The package also includes bindings to GtkExtra, which are used in the vwhere visualization and filtering guilet, as well as a gdk-pixbuf loader for the FITS image file format widely used within astronomy, and an easy-to-use but powerful image compositing, display, and output tool.
Enhancements:
VWhere 1.3.9:
- When a vector is passed with the & operator VWhere will reflect the proper variable name in the Axis Expression window, instead of assigning the less-meaningful "arrayN".
imdisplay 0.3.4:
- new "panes" option added, to support display of multiple images using either horizontal or vertical tiling
- multiple animations may now be displayed, and even commingled alongside static images
- fill rule may now be specified in an option string, and now defaults to "scale" instead of "none"
- imdisplay_defaults() function added, for option persistence
- 1D images which can be reshaped to NxN are now accepted
changed S-Lang semantics of C Gdk function void gdk_window_get_frame_extents(GdkWindow, &GdkRectangle) to GdkRectantle gdk_window_get_frame_extents(GdkWindow)
- more sophisticated placement/reparenting strategies for win chaining
- rgbwidget version 0.3.0, which adds POW scaling and version info

WhereIsM13 is a free Java application designed to help us break out of our habitual way of perceiving the night sky as two dimensional.

It does this by displaying the common Messier objects in their three dimensional positions within or around the Milky Way.

Note: A more advanced version of this application is in the works. It will have:

- A more extensive object catalog
- The ability to zoom in and out of the galaxy view
- The ability to click objects plotted in the galaxy view to display their names and statics
- Printing
- Many other enhancements

Planets is a simple interactive program for playing with simulations of planetary systems, released under the GPL. The project runs on Linux and Windows, and could doubtless be ported to your favorite flavor of Unix.
Planets was originally designed for kids, in particular, for my then 4-year old nephew who is fascinated by astronomy. The user interface is aimed at being simple enough that a fairly young kid can get some joy out of it. But the adults who have used it have found it to be pretty fun as well.
The code is not bug-free, and Planets is missing some significant features. But its pretty stable and is a fun toy to play with. If you do download it, please drop me an email and tell me about your experience with it.
Main features:
- Saving and loading of universes
- Infinite undo (erase last action) and goback (return to point in time just after last action). This allows for undoing mistakes and replaying interesting configurations.
- Traces of planet trajectories
- Two ways of dealing with planet collisions:
- merges, where the colliding planets are merged into one planet, and
- bounces, where the colliding planets are bounced off each other elastically. This itself comes in two varieties:
- force bouncing, where the force between planets is made repulsive at close quarters.
- true bouncing, where simple pool-table physics calculations are made to determine when planets collide, and compute the appropriate bounce from said collision.
- kidmode, a mode where the focus is (mostly) locked on the application, and interesting changes are initiated by merely banging on the keyboard. This mode is aimed at 1-5 year olds.
- Center-of-mass following: it is possible to follow the center of mass of a subset of the planets. Thus, if you have a sun-moon-planet system, you can have the view automatically track the moon-planet pair.
- Can display kinetic, potential and total energy of the system.
- Both the gravitational constant and the gravitational exponent can be changed.
- There is a simple control panel that makes it possible to see and change the simulation options.
- Zooming, panning, and centering on the center of mass.

SkyServer streams live astronomical data to file at user-specified intervals.
SkyServer is a computationally rigorous backend for planetaria, sky charts, ephemerides, astrological, or any application that may need to use realtime celestial data, making such data continuously available for processing either textually or graphically by your display script.
SkyServers astronomy libraries, written in Delphi-mode extended Pascal, have a ten-year pedigree. They are proven, stable, fast, and arc-second accurate, serving as the computation engine behind such well-regarded software products as Coeli Stella 2000, Adastra, DeskNite, and several other shareware titles for MS Windows.
SkyServers initial data set comprises a 15,695-star selection from the Yale and Hipparcos catalogs; Critical, NEO, bright, and transneptunian asteroids; DSOs, comets, sun, moon & planets, plus linesets for drawing, including constellation lines, boundaries, grids, aequator, ecliptic, horizon, galactic equator, polar points, and Milky Way.
Further data extensions may be obtained direct from Coeli. Extensions feature the complete SAO and Hipparcos star catalogs, regularly updated orbital elements for comets and asteroids, and nearly 300 extra star names and associated notes, all suitable for loading straight into SkyServer.
SkyServer dishes your data out in digestible form. Readable by both human and software, there are two principal file formats: "record jar" and rdb tables.
The latter may be manipulated at the command line without modification using a relational database tool such as NoSql. The record jar file is designed to be read in by a display script or simply perused by the user. See below for an example record from stars.data.
While the underlying Coeli engine has been tried and tested to production standard and been in constant development for over a decade, the SkyServer POSIX daemon itself is a first beta release. It needs testers and contributors, and I hope you will join the project.
Our aim is to offer a free, comprehensive, complete, yet extensible backend for astronomy scripting, thus rendering the hitherto daunting task of creating personalized astronomical applications for web or desktop a trivial matter. Whatever your style or preference - whether this be C, Java, Python, Ruby, Perl, PHP, or shell - SkyServer will provide the celestial data in realtime, right down to the screen coordinates of each and every object in its database, pixel-ready.
Your own display script will not need to do a single calculation.
Enhancements:
- A command line parser was implemented for SkyServer, incorporating a brief help page, version, options, and licensing information.
- Documentation was expanded to include instructions on runtime control via IPC signals.
- Planet, comet, and asteroid displays were added to the SkyShow GTK+ frontend, and the title-bars N/S E/W "facing" bug was fixed.

INDI is an instrument-neutral distributed interface control protocol. INDI aims to provide backend driver support and automation for a wide range of astronomical devices (telescopes, focusers, CCDs, etc.).
Current supported devices include many telescopes, CCDs, filter wheels, focusers, and video cams. INDI is used in popular astronomy suites like Xephem, KStars, DCD, and Cartes Du Ciel.
Enhancements:
- This release adds two new devices, improves INDI server performance, and introduces inter-driver communication among drivers.
- It has many bugfixes.