Siderial Time Calculator (c) dhwi

This applet calculates the siderial time and value to select on the TAL scope RA scale. Just enter your local longitude (eastern longitudes are negative) and the RA hours and minutes of the star you want to look at. Click on the run button, or wait a few moments. The applet has a timer, which will update the calculated results - siderial time for GMT, for your local observation place, and the value to set on your TAL RA setting circle - every few seconds.

You can also download the jar file and run it as a standalone application. In this case, you will get an additional exit button, and your local longitude will be saved for the next time.

If you have Java 1.3 or higher installed on your computer, you can just start it with

java -jar Siderial.jar

or, even more simple, just click on it (on Windows).

Otherwise, make sure the Siderial.jar file is in your classpath, either by setting an environment variable, or passing it as a command line parameter, and start it with

java Siderial

You can download the jar file here.

New Version 2004-1-17: Thanks to Dave for pointing out a problem with the Local Siderial Time display.