KStars is a an open source freeware planetarium program from KDE, the linux platform group. KStars is available for Windows, requires the Microsoft Visual C++ 2015 Redistributable to run on PCs and it will automatically download it if it is not installed.
The program features 100 million stars, 13,000 deep-sky objects and thousands of comets, asteroids, satellites and other sky object in its catalogue. Objects can be added manually or via other downloaded add-ons (see the Data menu).
As with other similar programs choosing a location is the first task after running the program. The program can import and use .fits images for detailed imagery. Moving the mouse object names are displayed as tool tips and right clicking on any provides a wealth of information about the object including viewing images and the option of adding it to a wishlist for observing.
The program window can of course toggle on and off display of horizon, stars, deeps sky objects, planets, milky way, equatorial grid, constellation lines, names and art and also supernovae and satellite positions.
Besides viewing the sky from any location one can also chose a time to view the sky, choose any set time or move in steps to the past or the future. The passage of time can also be sped up to view the changing sky faster. The Pointing menu can change the view based on which direction the viewer is looking at and also center on an object and keep tracking it.
The Tools that come with KStars are really useful for both the amateur sky watcher – with an ‘auto suggest’ tool in the works – and the professional. The calculator provides a lot of information such as object positions, coordinates and radial velocities, Julian dates and sun and moon rise and set times. The Observation planner displays information based on a chosen object, a list can be created and saved for any upcoming sky viewing. The planner includes a ‘What’s up tonight’ tool and the objects added to the wish list can be viewed here. The Sky calendar displays or plots planets’ tracks in the sky.
The program also supports interfacing – using INDI and KDE’s own Ekos platforms – with telescopes to drive the viewer to an object and capture images.
A KStar handbook is accessible from the help menu that provides a wealth of info on every feature available.