Main Window
The main window is where you build, configure, and generate ephemeris studies. Its title bar reads Cygnus - [workspace name], so you always know which workspace you are working in.
To start Cygnus:
- Double-click the Cygnus shortcut (the desktop or Start menu shortcut on Windows, the Applications folder entry on macOS).
The window opens centered on screen with an empty workspace, an empty Studies list on the left, and a large watermark of the application icon filling the content pane on the right because no study is selected yet.

Window Layout
The main window is organized into the following areas:
- Menu Bar: the complete inventory of everything Cygnus can do, grouped into five menus. See Menu Bar.
- Toolbar: a strip of icon buttons below the menu bar giving one-click access to the commands you use most often. See Toolbar.
- Status Indicators: two lights at the top right that report whether a study is generating records and whether your work is saved. See Status Indicators.
- Studies List: the resizable panel on the left listing every study in the current workspace. Selecting a study loads its editor into the content pane. See Studies List.
- Study Content Pane: the large area on the right that holds the selected study's editor. Every study type puts its settings in a column on the left and its results, an ephemeris table or a graph, on the right.
A splitter sits between the Studies list and the study content pane, so you can give either side more room.

Other Main Window Commands
- Toggle Theme: switch the whole interface between the Light and Dark themes. See Toggle Theme.
- Exit Application: close Cygnus, with an offer to save first if the workspace has unsaved changes. See Exit Application.