Working on the KStars Planetarium helps you gain knowledge in two different fields: astronomy and computer science. By claiming this task, you will dive and learn more about atmospherical refraction, as well as refactor or improve several lines of code.

Atmospherical refraction is a physical phenomena which modifies the true positions of the stars (including our Sun) on the sky, especially when they are very close to the horizon. When stars are near the horizon, their positions are altered due to multiple atmospheric layers through which the light passes to reach the observer. Because of refraction when you actually 'see' a sunset, the Sun is well below the horizon already.

KStars has the option to take into consideration these effects and compute the apparent position of the celestial objects, actually seen by the observer. The code which handles this is current in the SkyPoint class. It lacks of proper documentation, and further research about possible optimizations are required.

The outcome is reflected in the suggested steps for this task:

1. Make sure you understand the physical process, then read the currently implemented solution. (1 day)

2. Document about other existing numerical formulas recommended to do this computation.Tell us about what you have found and which one you consider most efficient. (1 - 2 days)

3. If you find a better algorithms or optimisations you will add them to the existing code. If not, this step will consist on refactoring the existing code (distributing it into the SkyPoint class and document it). (1 day)

4. Write an entry for the AstroInfo to detail how refraction is computed in KStars. (1 day)