VStar is a visualisation and analysis tool for variable star observation data developed in collaboration with the American Association of Variable Star Observers (http://www.aavso.org/) and the Citizen Sky project.

VStar can load observation data from files, URL-accessible data, or the AAVSO International Database, display interactive light curves and phase plots, and perform period analysis.

Plug-ins allow VStar's functionality to be extended.

In order to run VStar, you need to have version 1.8 or higher of the Java runtime installed on your computer. For more, see:

• Oracle or
• Amazon Corretto

Releases for Windows, Mac OS X and Linux (or other Unix variants or bash shells) are available: https://github.com/AAVSO/VStar/releases

Open vstar-mac.dmg and copy the VStar application to a location of your choice, along with the Extras folder if desired.

Extract vstar-win.zip to a location of your choice or run the installer by first extracting VStarWinSetup-x.y.z.zip.

Extract vstar-bash.zip to a location of your choice.

VStar can be launched by one of the following methods:

• Mac OS X: double-clicking the VStar launcher application.
• Windows: double-clicking the VStar.exe launcher application. See https://github.com/AAVSO/VStar/wiki/Installation-Recipes for more details.
• Linux (or other Unix variants or bash shells): running the VStar.sh shell script.

For more information about installing and running VStar for each operating system or environment, see https://github.com/AAVSO/VStar/wiki/Installation-Recipes

If you downloaded a VStar distribution, you will find a data directory containing sample variable star data files mostly taken from the AAVSO International Database. These example data files are also available here:

https://github.com/AAVSO/VStar/tree/master/data

To open a data file in VStar:

1. Select New Star from File... from the File menu.
2. Navigate to the data directory via the file dialog.
3. Choose a file, e.g. eps_aur_2445000.csv.

For more complete documentation, see the VStar User Manual.

The file build.xml is an Ant file used for building a VStar distribution jar file from source. This is not necessary if you just want to run VStar. Ant can be downloaded from http://ant.apache.org/ and 1.7.0 or higher is assumed. Type ant -p to see the options.

The src directory contains the Java source code for VStar.

The most recent version of the source code may be obtained from the VStar GitHub repository at https://github.com/AAVSO/VStar

The file extlib/ReadMe.txt details additional Java libraries that are required (and should already be present as part of this distribution) to build and run VStar.

The test directory contains unit tests. For testing, JUnit 3.8.2 is assumed (http://www.junit.org). See also extlib/ReadMe.txt for more about testing libraries.

VStar is licensed under the GNU Affero General Public License, version 3. See doc/license or http://www.gnu.org/licenses/agpl-3.0-standalone.html for details.

For licensing and links to source code for the external libraries used by VStar see the included extlib/ReadMe.txt file.