Solar System Barycenter Ephemeris

I have put together an ephemeris of the relationship between the Sun and the Solar System Barycentre, starting 3000BC to 3000AD, with longitude, distance, angular momentum, and torque every 5 days for the full 6000 year period.

It is compressed in an 11.6MB ZIP file which decompresses to a 30MB tab seperated values text file – you can download it from from this file storage page or this one – you are welcome to use it for any non-commercial purpose.

Update:  you can download it from it’s new home at:

The first character on each line is a ‘-‘ or a ‘ ‘ (blank space), being BC or AD, immediately followed by the date in YYYYMMDD year.frac format, the next column is ecliptic longitude in degrees, then distance in solar radii, angular momentum in grams cm2 / secs, and torque as delta_angular_momentum / delta_time_seconds, which as far as I can determine should match Dr Landscheidt’s work.

The angular momentum and torque calculations were done using a simple program I wrote in THINK Pascal running in Classic mode (OS9.2.2) in OSX10.3.9 on a 400 mHz Mac G4 Sawtooth.

The Astronomical Computations for the SSB were generated by…
Solar System Dynamics Group,
Horizons On-Line Ephemeris System
4800 Oak Grove Drive,
Jet Propulsion Laboratory
Pasadena, CA 91109 USA
Connect : telnet:// (via browser)
telnet 6775 (via command-line)
Author :

Update 24 May 2007:
I have made the following graphs of the full 6000 years for distance, angular momentum, and torque:
Sun - SSB distance 6000 yrs graph
Sun - SSB angular momentun 6000 yrs graph
Sun - SSB torque 6000 yrs graph

There are some interesting longer term cycles apparent in the envelopes.

4 comments on “Solar System Barycenter Ephemeris

  1. For those who might be interested in converting distance from Solar Radii to other units, you can convert to km by multipling by 696000, and from km to AU by dividing by 149597870.691

  2. Question: What is the longitude’s reference frame?
    I assume solar ecliptic, but is the zero point based
    on Geo Spring Equinox, fixed to J2000 or is it dynamic?

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