
Local Coordinates
General Description
This program simulates the position of a star in local (Altitude/Azimuth) coordinates. The horizon is shown along with the four cardinal directions (N, E, S, and W). The latitude of the observer is set at 35.5 degrees which sets the location of the north celestial pole (teal) relative to the northern horizon. The position of the star can be changed by using the Altitude and Azimuth sliders.
This simulation is part of a sequence of simulations used to introduce students to equatorial coordinates and the celestial globe. These additional simulations can also be found on the OSP ComPADRE site.
Local Coordinates Frame
- Display Options Menu
- Show Cardinal Arrows: show a second frame that displays a view of the sky overhead as seen by the observer whose horizon plane is shown in the Celestial Globe frame.
- Show Celestial Axis: show the celestial axis.
- Show Celestial Equator: show the plane of the celestial equator.
- Visual Elements
- Orange arrow: arrow from observer to the point with the altitude and azimuth given by the sliders.
- White dot: star with the altitude and azimuth given by the sliders.
- Green plane: the horizon plane of an observer on Earth. Objects above the horizon are visible to the observer, objects below the horizon are not.
- Black arrows (and labels): points in the four cardinal direction along the horizon plane.
- Pink line: the celestial pole.
Controls
- Altitude (deg): sets the azimuth of the star based on the observer's location. 0 degrees is on the horizon, while 90 degrees is the zenith.
- Azimuth (deg): sets the azimuth of the star based on the observer's location. 0 degrees represents N, 90 West, etc.
Mario Belloni (mabelloni@davidson.edu)
Todd K. Timberlake (ttimberlake@berry.edu)