Vulcan Calculation

As Vulcan is a hypothetical planet, there is no officially accepted ephemeris for the calculation of its position. However, two of the more widely used methods of calculating its position have been included in Solar Fire, and it is possible to choose which of these methods you would like to be used whenever Vulcan’s position is calculated. In the "Preferences" dialog, "Calculations" tab the possible methods are...

L.H.Weston - Professor Weston produced a set of orbital parameters for Vulcan based on a number of supposed sightings during last century and early this century. This proposed orbit has Vulcan orbiting the Sun once every 19.5 days, and having a maximum orb of about 8° from the Sun, as observed from the earth. The complete theory is published in the booklet “The Planet Vulcan”, published by the American Federation of Astrologers, Inc. Some doubt has been cast on the correspondence of this proposed orbit with the observations on which it is based, but no alternative has yet been proposed.

D.Baker - Dr Baker has documented a theory for Vulcan based on a quantum mechanical type of behavior. Vulcan is positioned 3° from Mercury in the direction of the Sun. If Mercury is within 3° of the Sun, then Vulcan is conjunct the Sun. It is always on the same side of the Sun as Mercury. The full rationale behind this concept is explained in his Dictionary of Astrology.

When this option is changed, any charts that are subsequently opened or calculated will use the newly selected calculation method, but charts that have already been calculated retain the option that was in effect when they were calculated.