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Heliocentric Ephemeris Study

A heliocentric ephemeris study produces a table of positions measured from the center of the Sun, in a Sun-centered coordinate system. Each body's motion reflects its own orbit rather than the Earth's viewpoint, which is what makes this the perspective for heliocentric analysis and research.

The editor puts the study settings in a column on the left and the generated ephemeris table on the right.

A generated Heliocentric Ephemeris Study whose ephemeris table reports Earth, Mars, and Jupiter by sign.

Create and Generate the Study​

To produce a heliocentric ephemeris:

  1. Click Ephemerides → Heliocentric Ephemeris on the menu bar.
  2. Configure the Basic Ephemeris Settings (Location, Zodiac, Ref. Plane).
  3. Configure the Ephemeris Date Range (Start Date, Start Time, End Date, Interval, Time Unit).
  4. Check the bodies you want in the Bodies list and the measurements you want in the Metrics list.
  5. Click the Run button beneath the ephemeris table.

A Heliocentric Ephemeris Study with Venus, Earth, Jupiter, and Saturn checked in the Bodies list and no records yet.

Step 1 is performed on the Ephemerides menu:

The Ephemerides menu with Heliocentric Ephemeris highlighted as the last entry in the tabular study group.

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

caution

A location is required even though heliocentric positions do not depend on one. Cygnus calculates and displays each record's date and time in the location's time zone, so no ephemeris can be produced without a place. See Locations Editor.

Bodies​

A heliocentric study offers 24 bodies under five classification groups: Planets, Barycenters, Asteroids, Centaurs, and Uranians. Bodies with no heliocentric meaning are absent, so there is no Diurnal Angles group and no Lunar Axis group.

The Sun and the Moon are also absent: the Sun is the center of the coordinate system, and the Moon is an Earth satellite. Earth appears in their place as an orbiting body. See Bodies List for the full catalog.

Measurements​

Five body metrics are available for the table.

Ecliptic reference planeEquatorial reference planeWhat it reports
LongitudeRight AscThe body's position along the reference plane, in degrees.
Sign PositionSign PositionThe body's position expressed within its zodiac sign.
LatitudeDeclinationThe body's position perpendicular to the reference plane, in degrees.
DistanceDistanceThe body's distance, in AU.
SpeedSpeedThe body's rate of motion, in degrees per day.

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: