Programme by Session

Desktop planetarium programs have largely replaced the planisphere as favourite tool for a comfortable visualisation of the starry sky for every place and time on the Earth's globe. A popular program is the free and open-source Stellarium which delivers arguably the most visually realistic simulation of the night sky. Since 2010 the author is member of the Stellarium development team and is working on improvements that make this program more accurate for long-time simulations and applications in the context of cultural astronomy. The most important development was the introduction (together with students at TU Wien) of a 3D landscape and architecture rendering module which allows the study of the interplay of sky, landscape and architecture, orientation of buildings towards points of astronomical interest (e.g. solstice sunrise), and light and shadow interaction for sites of alleged astronomical use. Recently, even the temporal development of the building model can be studied, so that the time control of Stellarium also controls the architectural changes a monument may have undergone over centuries of use. Comparing photos with simulated views in a model created from laser scan data gives a very promising indicator that this method provides a reliable simulation.
For simpler applications, a panorama photograph can be created and carefully adjusted to act as “dependable proxy” of the real landscape horizon for single viewpoints.
However, Stellarium is not perfect yet. Users should be aware of a few remaining shortcomings, and also in general of pitfalls when dealing with the simulations of historical sky views.