Maximum Elongations Study
Elongation maxima are the moments at which Mercury and Venus are best placed to be seen, and they punctuate the synodic cycle at points no aspect marks. The Maximum Elongations study dates them across the range you set.
The study generates an event each time an inferior planet reaches its greatest angular distance from the Sun. Each event carries the planet's position and motion at that moment, together with the Sun's.
Create a Maximum Elongations Study
To add a Maximum Elongations study to the current workspace:
- Click Mundane Studies → Longitudinal Studies on the menu bar.
- Click Maximum Elongations in the Longitudinal Studies submenu.
Alternatively, click the Arc Studies drop-down button on the toolbar and select Maximum Elongations 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
An elongation is the angular distance between a planet and the Sun. At maximum western elongation the planet is visible in the eastern sky before sunrise; at maximum eastern elongation it is visible in the western sky after sunset. The study records the instant of each maximum, along with the angle reached.
Its settings carry an Event Type drop-down, which restricts the study to one side or the other, and a Bodies selection list offering only Mercury and Venus, the two planets that can reach maximum elongation.
Events Table Columns
The events table lists one row per maximum. 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 header text of the coordinate columns follows the study's Reference Plane: they read Longitude and Latitude in the ecliptic plane and Right Asc and Declination in the equatorial plane. The table below uses the ecliptic-plane headers.
| Column | Description |
|---|---|
| Date Time | Date and time the event perfects, in the application's long date-time format. Always the first column, and it cannot be moved. Visible by default. |
| Event Type | Which maximum the event records, a western elongation or an eastern one. Visible by default. |
| Body | Name of the celestial body. Visible by default. |
| Body Longitude | The body's primary coordinate in degrees. Hidden by default. |
| Body Sign | The body's position as degrees, sign and minutes of the zodiac. Visible by default. |
| Body Latitude | The body's secondary coordinate in degrees. Hidden by default. |
| Body Distance | The body's radial distance in astronomical units (AU). Hidden by default. |
| Body Speed | The body's speed in degrees per day. Hidden by default. |
| Elongation | The body's angular distance from the Sun in degrees. Visible by default. |
| Sun Longitude | The Sun's primary coordinate in degrees. Hidden by default. |
| Sun Sign | The Sun's position as degrees, sign and minutes of the zodiac. Visible by default. |
| Sun Latitude | The Sun's secondary coordinate in degrees. Hidden by default. |
| Sun Distance | The Sun's radial distance in astronomical units (AU). Hidden by default. |
| Sun Speed | The Sun's speed in degrees per day. Hidden by default. |
| Event Interval | Elapsed time since the previous event in the list. Hidden by default. |