written by Mario Belloni and Todd Timberlake

The Equatorial Coordinates model displays the position of a star in equatorial (Right Ascension/Declination --- RA/Dec) coordinates. The horizon is shown along with the four cardinal directions (N, E, S, and W). The Latitude slider changes the latitude of the observer which is shown by the change in the (teal) celestial pole relative to the northern horizon. The position of the star can be changed by using the Right Ascension and Declination sliders. Once these coordinates are selected, pressing the play button will put the star, celestial grid, and the equatorial coordinates in motion to simulate the 23 hour and 56 minute motion of stars in the night sky.

Equatorial Coordinates model is distributed as a ready-to-run (compiled) Java archive.  Double clicking the ejs_astronomy_EquatorialCoordinates.jar file will run the program if Java is installed.  You can modify this simulation if you have EJS installed by right-clicking within the plot and selecting "Open EJS Model" from the pop-up menu item.

• Download ejs_astronomy_EquatorialCoordinates.jar - 2507kb Java Archive File

Last Modified June 6, 2014

This file has previous versions.

Source Code for the Equatorial Coordinates Model program.

• Download ejs_astronomy_EquatorialCoordinates.zip - 35kb Compressed File

Published November 14, 2009
Last Modified June 6, 2014

This file has previous versions.