Jyotisa is the vedic system of astronomy and astrology. It has three branches:
1. Siddhanta: Indian astronomy.
2. Samhita: Mundane astrology, predicting important events based on analysis of astrological dynamics in a countries horoscope or general transit events such as war, earth quakes, political events, financial positions, electional astrology; house and construction related matters (Vastu Shastra), animals, portents, omens etc.
3. Hora: Predictive astrology based on analysis of natal horoscopes and the moment a query is made.
There are two main systems of Vedic astrology practiced today: Parashari and Jaimini which were developed by the sages Parashara and Jaimini respectively. The sage Parashara is said to be the "father of Vedic astrology" who recorded the main principles of vedic astrology or "jyotish", the science of light, into the classic Sanskrit text known as the Brihat Parashara Hora Shastra. This forms the basis for the entire Parashari system, which is by far the most widely used in India and the world today.
Astrology remains an important facet in the lives of many Hindus. In Hindu culture, newborns are traditionally named based on their jyotish charts, and jyotish concepts are pervasive in the organization of the calendar and holidays as well as in many areas of life, such as in making decisions made about marriage, opening a new business, and moving into a new home. To some extent, astrology even manages to retain a position among the sciences in modern India.
A panchangam is a Hindu astrological almanac (or calendar), which follows traditional Indian cosmology, and presents important astronomical data in tabulated form. It forecasts celestial phenomena, such as solar eclipses, and weather (rain, dryspells), as well as more mundane occurrences.
Lagna - the ascendant
One's ascendant, or lagna, the rashi which is rising on the eastern horizon at the time of one's birth, is the most influential and important one. Of lesser importance but still some impact is the Janma Rashi, the rashi in which the moon lay while one was born.
Some important special lagnas are follows.
1. Chandra Lagna (ascendant counted from natal Moon sign - very important lagna)
2. Surya Lagna (ascendant counted from natal Sun sign)
3. Karak Lagna (significator taken as ascendant for all grahas)
4. Varnada Lagna (for social company)
5. Shri Lagna (for prosperity and marriage)
6. Indu Lagna (for wealth)
7. Hora Lagna (for financial prosperity)
8. Gati Lagna (for name and fame)
There are three different Jyotish chart notations, for showing the rashi (signs) and bhava (houses) which are functionally equivalent but quite different in appearance. The following images show the same birth chart in the two main notations - North Indian and South Indian. The third notation is followed in Eastern parts of India.
The Bhrigu Samhita is an astrological (Jyotish) classic attributed to Maharishi Bhrigu during the Vedic period, although the available evidence suggests that it was compiled over a period of time by the various sishyas (students in the lineage) of Maharishi Bhrigu.
Maharishi Bhrigu was the first compiler of predictive astrology. He compiled about 500,000 horoscopes and recorded the life details and events of various persons. These Horoscopes were based upon the planetary positions of the Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Rahu (North Node of the Moon) and Ketu (South Node of the Moon). After that, Maharishi Bhrigu gave his predictions on different types of horoscopes compiled by him with the help of Lord Ganesha in a brief and concise manner. The total permutations/possible horoscope charts that can be drawn with this is about 45 million.