StarTrack

StarTrack simulates apparent trajectory of fixed stars on the sky. Based on the geographic position of the observer, and the azimuth and declination angles of the observed star, this app calculates the apparent motion of the star in real time. It can be used to check the motion of astronomy telescopes.

The initial parameters are shown below a simple graphics of the sky. The trajectory of the star is shown with an orange-blue curve, where orange indicates, that the star is above the horizon, while blue indicates, that the star is below it. The position of the star is shown with a red dot. A smaller dot indicates the position of the polar point of the sky. The direction of the azimuth is also shown with a red radial line. The initial latitude is read from the device, but can be modified. The parameters Latitude, Declination, Azimuth and Direction can be changed by touching the corresponding labels. To start the simulation, press the Start button. Impossible situations are filtered out.

Note, that the center of the compass points to the Zenith, hence the directions of West and East are swapped.