Techniques

Indian astrology. The word means "the science of light" and classically covers three limbs: ganita (calculation), samhita (mundane and collective matters) and hora (the horoscope of an individual). Most of what is called Jyotish today is the third limb.

A birth chart — a diagram of where each graha stood, as seen from one place on Earth, at one moment. It needs three inputs and no more: date, time and place of birth. Everything else in a reading is derived from those three.

The angle between the tropical zodiac (measured from the equinox) and the sidereal zodiac (measured from the fixed stars). It grows by about 50 arcseconds a year because of the precession of the equinoxes, and is currently around 24°. Choosing a different ayanamsha shifts every position in a chart, which is the single largest source of disagreement between two Jyotish readings of the same birth.

The ayanamsha adopted by the Indian government's Calendar Reform Committee in 1955 and used by the national ephemeris. Also called Chitrapaksha, because it fixes the star Spica (Chitra) at 180°. It is the default on this site — not because it is provably right, but because it is the one most Indian readings assume.

Aspect — the influence a graha exerts on another place in the chart. Every graha aspects the seventh house from itself. Mars additionally aspects the 4th and 8th, Jupiter the 5th and 9th, and Saturn the 3rd and 10th; these three special aspects belong to exactly the superior planets among the classical seven. Note that Jyotish aspects count whole signs, where Western astrology measures degrees.

Transit — where the grahas are now, as against where they stood at birth. Read against the birth chart, usually from the Moon sign in Indian practice rather than from the ascendant.

The Indian almanac. The name means "five limbs": tithi, vara, nakshatra, yoga and karana. Four of the five are computed from the angular relationship between the Sun and the Moon, which is why a panchanga is really a lunar-solar instrument.

A lunar day — the time the Moon takes to gain 12° on the Sun. Because that gain is not uniform, a tithi runs between roughly 19 and 26 hours, so it does not line up with a calendar date and can be skipped or repeated.

Half a tithi — the Moon gaining 6° on the Sun. There are eleven karanas, of which four are fixed and seven repeat, giving sixty in a lunar month.

Choosing an auspicious time to begin something. Also the name of a specific unit — one-thirtieth of a day, about 48 minutes. Muhurta is the most widely practised branch of Jyotish in India and the one least dependent on a birth chart.

A significator — the graha that stands for a particular matter. Some are fixed by tradition (the Sun for the father, the Moon for the mother); others are assigned per chart by degree, as in the chara karaka scheme.

The "soul significator" — the graha at the highest degree within its sign, excluding Ketu in most schools. Central to Jaimini methods, where it is read as the chart's governing theme.

A scoring system that awards each sign points (bindus) from the perspective of each graha, producing a numerical map of where a chart is strong. Widely used for transit judgement because it turns a qualitative reading into a comparable number.

"Six strengths" — a classical scheme that scores each graha on six separate measures (positional, directional, temporal, motional, natural and aspectual) and sums them. One of the few parts of Jyotish that is fully arithmetical, and therefore reproducible between practitioners.