Retrograde Cycles Study
A retrograde period is a span, not a moment, and the Retrograde Cycles study delivers the whole cycle as a single row rather than leaving you to assemble it from separate station events. It generates an event for each complete retrograde cycle of a body, keyed to the moment the body enters its pre-retrograde shadow, which is the chronological start of the cycle.
Each event carries the exact times, positions and intervals of the pre-shadow entry, the retrograde station, the direct station and the point at which the body leaves the post-retrograde shadow.
Create a Retrograde Cycles Study
To add a Retrograde Cycles study to the current workspace:
- Click Mundane Studies → Stations on the menu bar.
- Click Retrograde Cycles in the Stations submenu.
Alternatively, click the Station Studies drop-down button on the toolbar and select Retrograde Cycles from its flyout.
The new study appears at the bottom of the Studies list and is selected automatically, so its settings open immediately. It takes its name from the study type.
What This Study Finds
One event is generated for each complete retrograde cycle a body passes through. The row is dated to the pre-shadow entry, the chronological start of the cycle, and from there it follows the cycle through its retrograde station, its direct station and its exit from the post-retrograde shadow.
Because a whole cycle is gathered into one row, the intervals between its landmarks are listed alongside them: the length of the pre-shadow period, the length of the retrograde period itself and the length of the post-shadow period, each in days.
The settings column holds the Study Name, the ephemeris settings and the study date range, followed by a single Bodies selection list holding the bodies whose cycles are wanted.
Events Table Columns
The events table lists one row per cycle. Several columns are hidden by default, as the table notes. Right-click any column header to show or hide a column, as described in Choose Events Table Columns. The coordinate columns follow the study's Reference Plane: their headers read Longitude and Latitude in the ecliptic plane, and Right Asc and Declination in the equatorial plane. The table below gives the ecliptic-plane headers.
| Column | Description |
|---|---|
| Date Time | Date and time the body enters its pre-retrograde shadow, in the application's long date and time format. Always the first column, and it cannot be moved. Visible by default. |
| Body | Name of the celestial body. Visible by default. |
| Pre-Shadow Entry Longitude | Primary coordinate at the pre-shadow entry, in degrees. Hidden by default. |
| Pre-Shadow Entry Sign | Position at the pre-shadow entry, as degrees, sign and minutes of the zodiac. Hidden by default. |
| Pre-Shadow Entry Latitude | Secondary coordinate at the pre-shadow entry, in degrees. Hidden by default. |
| Pre-Shadow Period (days) | Number of days from the pre-shadow entry to the retrograde station. Visible by default. |
| Retrograde Station Date Time | Date and time the body stations retrograde. Visible by default. |
| Retrograde Station Longitude | Primary coordinate at the retrograde station, in degrees. Hidden by default. |
| Retrograde Station Sign | Position at the retrograde station, as degrees, sign and minutes of the zodiac. Visible by default. |
| Retrograde Station Latitude | Secondary coordinate at the retrograde station, in degrees. Hidden by default. |
| Retrograde Period (days) | Number of days from the retrograde station to the direct station. Visible by default. |
| Direct Station Date Time | Date and time the body stations direct. Visible by default. |
| Direct Station Longitude | Primary coordinate at the direct station, in degrees. Hidden by default. |
| Direct Station Sign | Position at the direct station, as degrees, sign and minutes of the zodiac. Visible by default. |
| Direct Station Latitude | Secondary coordinate at the direct station, in degrees. Hidden by default. |
| Post-Shadow Period (days) | Number of days from the direct station to the post-shadow exit. Visible by default. |
| Post-Shadow Exit Date Time | Date and time the body leaves the post-retrograde shadow. Visible by default. |
| Post-Shadow Exit Longitude | Primary coordinate at the post-shadow exit, in degrees. Hidden by default. |
| Post-Shadow Exit Sign | Position at the post-shadow exit, as degrees, sign and minutes of the zodiac. Hidden by default. |
| Post-Shadow Exit Latitude | Secondary coordinate at the post-shadow exit, in degrees. Hidden by default. |
| Event Interval | Elapsed time since the previous event in the list. Hidden by default. |