Elements of Astronomy and Astrological Calculations [AP]

Predictive astrology is based on the positions of planets, ascendant, expansion of bhavas etc. at the time of birth of a native or question. Horoscope, chalit charts and divisional charts are casted for that time. Now-a-days these are generated by use of computer. Sometimes mistake may appear due to programming error or some defect in the computer, so it is very essential for an astrologer to have the knowledge to check the corrections and accuracy of horoscope and other charts.

An astrologer must have preliminary knowledge of astronomy. These days normally astrologers do not observe the planets and other celestial bodies but use the longitudes, latitudes, declinations etc. observed by the observatories or calculated by traditional methods. Astrology is an experimental science and thus a very small error may cumulate to a big difference in several hundred years. So our traditional methods require some correction (Beeja sanskara).

We have adopted the positions of exalation and deblitation for a point of time that occured long time ago. Surya siddhanta clearly states that the Sun, Moon and other planets are exalted when they are at apogee (at maximum distance from the earth) and deblitated at perigee (at minimum distance from the earth). The major axis of the orbit of the Earth (apparent Sun), Moon and other planets are revolving slowly in the direction of revolution of the planets.

The apses of the orbit of the earth complete one revolution in more than one lac years resulting in change of longitude of exaltation and deblitation of the Sun. Shri Kedar Dutt Joshi, Reader in astrology, Benaras Hindu University, has also touched upon this matter in the preface of his book Tajik Neelkanthi. These days Sun is exalted around 4th July every year, when its longitude is nearly 78 (18 gemini).