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Geocentric Aspect Ephemeris Study

A geocentric aspect ephemeris study records both geocentric positions and the angular relationships between pairs of bodies, sampled at a fixed interval across a date range. It answers questions about how the angle between two bodies evolves over time, alongside the positions that angle is derived from.

Bodies are chosen in two lists, Inner Bodies (the aspecting set) and Outer Bodies (the aspected set), and every valid pairing between the two lists contributes its own aspect columns to the ephemeris table.

A Geocentric Aspect Ephemeris Study whose ephemeris table shows the Venus/Mars Phase and Separation columns.

The Two Tabs​

The settings column carries two tabs:

Create and Generate the Study​

To produce a geocentric aspect ephemeris:

  1. Click Ephemerides → Geocentric Aspect Ephemeris on the menu bar.
  2. Configure the Basic Ephemeris Settings (Location, Zodiac, Ref. Plane) and the Ephemeris Date Range (Start Date, Start Time, End Date, Interval, Time Unit).
  3. On the Inner & Outer Bodies tab, check the bodies in the Inner Bodies and Outer Bodies lists.
  4. On the Body & Aspect Metrics tab, check the metrics in the Body Metrics and Aspect Metrics lists.
  5. Click the Run button beneath the ephemeris table.

A Geocentric Aspect Ephemeris Study with Mercury checked in the Inner Bodies list and Jupiter in the Outer Bodies list.

Step 1 is performed on the Ephemerides menu:

The Ephemerides menu with Geocentric Aspect Ephemeris highlighted at the top of the middle group.

An Interval of 1 with a Time Unit of Days gives one record per day.

caution

A location is required even though geocentric positions do not depend on one. Cygnus calculates and displays each record's date and time in the location's time zone. See Basic Ephemeris Settings.

Bodies​

The Inner Bodies list offers the full 33-body Earth-frame catalog, including the Diurnal Angles group. The Outer Bodies list omits those four angles and offers the remaining 29 bodies, so an angle such as the Ascendant can take part in an aspect pair only as the aspecting (inner) member. See Bodies List.

Measurements​

Two metrics lists share the Body & Aspect Metrics tab.

The Body Metrics list adds positional columns for every selected Inner and Outer body: Longitude, Sign Position, Latitude, Distance in AU, and Speed in degrees per day. Under an Equatorial reference plane the first and third read Right Asc and Declination. On a new aspect study only Sign Position is checked.

The Aspect Metrics list adds relationship columns for every valid body pair.

Aspect metricWhat it reports
Cycle AngleThe angular distance from the outer body to the inner body in the direction of zodiacal motion, from 0 to 360 degrees.
PhaseWhere the pair sits in its cycle: New, Waxing, Full, or Waning.
SeparationThe shortest angular distance between the two bodies regardless of direction, from 0 to 180 degrees.

Phase and Separation are checked by default on a new aspect study.

note

These three metrics are the only aspect-related list in Cygnus. There is no editable list of aspect angles or aspect values anywhere in the application.

After the Records Are Generated​

The study locks when the generation completes, and the Run button becomes invisible until you unlock the study. Meanwhile you can read, arrange, search, copy, and export the results: