Equatorial Coordinates Model Documents

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Main Document

Equatorial Coordinates Model 

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.

Last Modified July 10, 2013

This file has previous versions.

Source Code Documents

Equatorial Coordinates Model Source Code 

Source Code for the Equatorial Coordinates Model program.

Published November 14, 2009
Last Modified November 14, 2009