Astronomy and Mathematical Astrology

Astronomy and Mathematical Astrology was the first book on astrology that I purchased. Correspondingly, I consider Deepak Kapoor to be my first guru on this subject.

The book starts with a general explanation of astronomy. These chapters present modern theory of astronomy, e.g. planets and how they revolve around Sun in the solar system, Kepler’s laws of planetary motions etc. These can be given a miss if one remembers the course work in Science and Physics during middle and high school. Still, the explanation is not out of place in this book where it helps to set the correct context and provides you with a quick refresher course if you need it.

It is important for any student of astrology to understand existence of Ayanmsha correction, Sayana and Niryana Systems and what westerners call First Point of Aries and how it is related to and yet different from Uttarayana that Indians have been following for centuries. The books explains these concepts in a simple language with a lot of illustrations and the subject matter is well organized. It also explains about existence and mathematics behind Rahu/Ketu, solar and lunar eclipses and most importantly retrogression.

I learnt how to prepare a horoscope from this book by referring to an ephemeris and learnt how to calculate ascendant, MC and degrees of the planets by taking all variables into account. There are quite a few softwares, free and paid, available on the internet (including my own), that can prepare a horoscope from date, place and time of birth. This makes the job of an astrologer quite easy, but it still is good to understand the basic principles.

In a separate chapter, this book explains how to calculate Vimshottari Dasha values by calculating balance of dasha at birth from longitude of Moon. It also helps understand divisional charts (navamsha, dashamsha etc.), panchanga (tithi, vaar, nakshatra, yoga and karana) and finally graha and bhav balas, i.e. strength of planets and houses in a horoscope.