The Study of Jyotisha · Chapter 6 of 54 · Part One · Beginnings

#Casting a chart

#What a chart is

A horoscope chart (kundali or jataka) is a diagram of the sky at one moment, seen from one place. It shows two things:

1. Where each graha is in the zodiac — its sign and degree.
2. Which part of the zodiac was rising on the eastern horizon — the lagna, or ascendant.

Everything else in the chart — the houses, the aspects, the strengths, the yogas, the planetary periods — is worked out from these two things. This chapter shows how to get them right. Today a computer does the arithmetic in a fraction of a second, but you should understand every step, because almost all mistakes in real charts come from the data that goes in, not from the arithmetic.

We will cast one complete example chart and use it again in later chapters:

Example: a person born in Hyderabad (17°23′ N, 78°29′ E) on Wednesday 15 August 1990 at 10:30 a.m. Indian Standard Time.

#Step 1: Check the birth data

You need four things:

1. The date.
2. The time, as accurately as possible, and which clock it was read from.
3. The place, as a latitude and longitude.
4. The time zone in force at that place on that date.

#Ask about the time carefully

The rising sign changes about every two hours, and its degree changes about every four minutes. A birth time that is fifteen minutes wrong can change the lagna's sign if the birth was near a boundary, and it always changes the planetary periods slightly. So:

• Ask where the time came from: a hospital record, a parent's memory, a horoscope written at the time by a family astrologer? Hospital records are usually best.
• Check a.m. and p.m. Twelve hours of error is a common and disastrous mistake.
• Remember that in the Indian reckoning the day begins at sunrise (Chapter 5). A birth "on the night of Monday" at 2 a.m. is Tuesday by the clock. Ask whether the family means the clock date or the panchanga day.

Varahamihira expected an astrologer to be able to check the lagna independently by observation, with a shadow-stick and instruments (Brihat Samhita II). The tradition also has methods for reconstructing a birth time that has been lost — a whole chapter of the Brihat Jataka is given to them (Brihat Jataka XXVI) — and Chapter 45 of this course explains how such methods are used and what their limits are. For now, the lesson is simple: garbage in, garbage out.

#Know which clock was used

Indian Standard Time (IST) is 5 hours 30 minutes ahead of Universal Time (UT). It is the time of the meridian 82°30′ east of Greenwich, which passes near Mirzapur. But it has not always been the only time used in India:

• Local mean time. Before standard times, and in many older family records, times were given by the local Sun. Local mean time differs from IST by 4 minutes for every degree of longitude east or west of 82°30′ E.
• City times. For some years after IST was introduced in 1906, Bombay and Calcutta kept their own local times (Calcutta until 1948, Bombay until 1955).
• War time. During the Second World War, from 1942 to 1945, Indian clocks were set one hour ahead of IST (5 h 30 m + 1 h = 6 h 30 m ahead of UT). A birth recorded as 10:30 a.m. in 1943 was 9:30 a.m. IST.
• Abroad. Many countries use summer time (daylight saving time). Always check whether it was in force.

The calculators on this website look up the time zone of the place and date for you, from the international time-zone database. But you should still ask the family whether the time was from a watch, a radio, a hospital clock or the Sun.

Example. Our person was born at 10:30 IST in 1990. There was no war time or local time in force, so:

10:30 IST − 5:30 = 05:00 UT on 15 August 1990.

For later use, we also want the local mean time. Hyderabad is at 78°29′ E, which is 82°30′ − 78°29′ = 4°01′ west of the IST meridian. 4°01′ × 4 minutes = 16 minutes 4 seconds. So local mean time is 10:30 − 0:16 = 10:13:56.

#Find the latitude and longitude

Use the latitude and longitude of the actual town, not the district or the state capital. A village 50 km away can be half a degree different, and that moves the lagna by a degree or two of the zodiac. The place search on this website covers every town and village in India listed in the Government of India's Local Government Directory.

#Step 2: Find the planets

The positions of the nine grahas are taken from an ephemeris, a table (or a program) that gives their positions for any moment. In the old days the astrologer computed them from a siddhanta, as Chapter 3 described; then printed almanacs and ephemerides took over; today a computer program does it.

The positions an ephemeris gives are usually tropical (measured from the March equinox). To get the sidereal positions Jyotisha uses, subtract the ayanamsa for the date (Chapter 2).

Example. For 05:00 UT on 15 August 1990, the Lahiri ayanamsa was 23°44′. Computed with this website's engine, the sidereal positions are:

Check this against what you learned in Chapter 3:

• Mercury is 27° from the Sun — within 28°, as it must be.
• Venus is 20½° from the Sun — within 47°.
• Saturn is retrograde. Chapter 3 said an outer planet goes retrograde when roughly opposite the Sun. Saturn is at 266°, the Sun at 118°: they are 148° apart, getting close to opposition. That fits.
• Ketu is exactly 180° from Rahu.

These quick checks catch most mistakes. Make a habit of them.

#Step 3: Find the lagna

The lagna is the point of the zodiac rising on the eastern horizon at the moment and place of birth. Modern programs compute it from a formula using the local sidereal time, the latitude and the tilt of the Earth's axis. The old astronomers had a method you can do by hand, and it is worth learning because it shows clearly what the lagna is.

#The idea: the zodiac rises sign by sign

The whole zodiac rises once a day. So if you know which point was rising at some moment, and how long each sign takes to rise, you can step forward from that moment to any other.

There is one moment when you always know which point is rising: sunrise. At sunrise the Sun is on the eastern horizon, so the rising point is (very nearly) the Sun's own position. From there, you step forward through the signs, using their rising times, until you have used up the time between sunrise and birth.

This is exactly the method the Surya Siddhanta teaches (Surya Siddhanta III.46–48). Burgess notes that the word lagna itself originally meant the point "attached" to, or "corresponding" to, a moment of time.

#Rising times of the signs

Signs do not all take the same time to rise. Near the equator they take roughly two hours each, but not exactly. The Surya Siddhanta gives the rising times "at Lanka" — on the equator — in units called asus or pranas ("breaths") of 4 seconds each (Surya Siddhanta III.42–45):

Away from the equator, the times change. In the northern hemisphere, the signs of one half of the zodiac rise faster and the other half slower. The Surya Siddhanta gives the correction for any place: for the first three and the last three signs it subtracts an amount called the charakhanda, which depends on the latitude, and for the six middle signs it adds the same amounts (Surya Siddhanta III.44–45).

There is one complication. The Surya Siddhanta's table was made when the sidereal and tropical zodiacs nearly coincided. Rising times really depend on the tropical position of a sign (its relation to the equator). Today, with the ayanamsa at about 24°, the sidereal signs sit about 24° away from where they were, so their rising times are different from the old table. The table below gives the actual rising times of the sidereal signs at Hyderabad in 1990, computed for this course:

Notice Pisces and Aquarius rise in about an hour and a half, while Scorpio takes over two and a quarter hours. At higher latitudes the difference is much greater: in northern Europe some signs rise in under an hour and others take over three. That is why the lagna is not simply "two hours per sign", and why a table for the right latitude is needed.

#Sidereal time, not clock time

One small correction. The zodiac turns once in a sidereal day of 23 hours 56 minutes, not 24 hours. So rising times are in sidereal minutes, which are a little shorter than clock minutes. To convert clock minutes to sidereal minutes, multiply by 1.00274 (that is, add about 10 seconds per hour).

#Worked example: the lagna by hand

1. Sunrise. At Hyderabad on 15 August 1990, the Sun rose (its upper edge appeared on the horizon) at 5:58:52 IST. At that moment the rising point was 27°23′ Cancer. (It is a little less than a degree behind the Sun at 28°12′ Cancer, because at the almanac's sunrise the centre of the Sun is still slightly below the horizon.)
2. Time from sunrise to birth. 10:30:00 − 5:58:52 = 4 h 31 m 08 s = 271.1 clock minutes = 271.1 × 1.00274 = 271.9 sidereal minutes.
3. The rest of Cancer. The rising point must travel from 27°23′ Cancer to 30° Cancer: 2°37′ = 2.62°. Cancer takes 132.5 minutes for 30°, so 2.62° takes 2.62 ÷ 30 × 132.5 = 11.6 minutes. Time left: 271.9 − 11.6 = 260.3 minutes.
4. All of Leo. 127.0 minutes. Time left: 260.3 − 127.0 = 133.3 minutes.
5. All of Virgo. 125.6 minutes. Time left: 133.3 − 125.6 = 7.7 minutes.
6. Into Libra. Libra takes 130.2 minutes for 30°. 7.7 minutes is 7.7 ÷ 130.2 × 30 = 1.77° = 1°46′.

So the lagna is about 1°46′ Libra.

The exact answer from the engine's formula is 1°50′ Libra. The hand method is off by only 4 minutes of arc, because it assumes each sign rises at an even speed, which is nearly but not exactly true. For a sign, that is plenty. The old astrologers refined it by dividing signs into smaller parts.

What the example shows is the essence of the lagna: it is time turned into space. Each four minutes of clock time move the rising point about one degree. This is why the birth time matters so much.

#The modern formula, for reference

For readers who want it, here is the formula programs use. Let:

• θ be the local sidereal time, as an angle (in degrees: hours × 15);
• ε be the obliquity of the ecliptic (about 23°26′);
• φ be the latitude.

Then the tropical ascendant A is given by

tan A = cos θ ÷ −(sin θ cos ε + tan φ sin ε)

taking care to put A in the right quadrant. Subtract the ayanamsa to get the sidereal lagna. You do not need to use this formula yourself; it is here so that nothing in the course is a black box. In our example the local sidereal time was 7 h 47 m 21 s (116°50′), and the formula gives a tropical ascendant of 25°34′ Libra; minus the ayanamsa of 23°44′, that is 1°50′ Libra.

#The midheaven

The point of the zodiac on the meridian — the highest point of the ecliptic at that moment — is called the midheaven or madhya lagna, "middle lagna". The Surya Siddhanta gives its rule in the same passage (Surya Siddhanta III.49). In our example it is 1°09′ Cancer. Indian astrology uses it less than Western astrology, but it matters for some house systems and for one of the strengths of planets (Chapter 14).

#Step 4: Number the houses

The twelve houses (bhavas) are the twelve areas of life the chart is read for — self, wealth, siblings, home, children, and so on (Chapter 9). They are counted from the lagna. There are several ways of drawing their boundaries.

#Whole-sign houses: the classical method

In the oldest and most common Indian method, the whole sign containing the lagna is the first house, the next sign is the second house, and so on round the zodiac. The degree of the lagna does not matter for this purpose — only its sign.

This is the method of Varahamihira: he defines the houses as counted from the rising sign, and uses the signs themselves as the houses throughout his book (Brihat Jataka I.15–19). It is the method of almost all classical Indian rules, and the method this course uses unless it says otherwise.

Example. The lagna is in Libra. So:

#Other house methods

Later authors also used systems in which the houses are not whole signs:

• Equal houses from the lagna degree. Each house is 30°, starting from the lagna's exact degree, or centred on it.
• Sripati's houses (bhava chalit): the space between the lagna and the midheaven is divided into three, and so on round the circle. The middle of each house is called its bhava madhya and the boundary its bhava sandhi. A planet near a boundary may "move" into the next house in this chart. Many Indian programs print this as a second chart called the chalit or bhava chart.

These systems are explained where they are used, in Chapter 14. For learning the classical rules, whole signs are enough, and much clearer.

#Step 5: Draw the chart

Indian astrologers draw charts in three main styles. All show the same information; only the layout differs. Learn to read all three, because you will meet all of them.

#The South Indian chart

In the South Indian style, the signs are fixed in a square of twelve boxes, always in the same places, going clockwise from Pisces at the top left. The lagna is marked in whichever sign it falls, usually with a diagonal line or the word "Lagna" or "Asc".

+------------+------------+------------+------------+
|  Pisces    |  Aries     |  Taurus    |  Gemini    |
|            |  Mars      |  Moon      |            |
+------------+------------+------------+------------+
|  Aquarius  |                         |  Cancer    |
|            |                         |  Sun  Jup  |
+------------+                         +  Ven  Ket  +
|  Capricorn |                         |  Leo       |
|  Rahu      |                         |  Merc      |
+------------+------------+------------+------------+
| Sagittarius|  Scorpio   |  Libra     |  Virgo     |
|  Sat (R)   |            |  LAGNA     |            |
+------------+------------+------------+------------+

The advantage: a sign is always in the same box, so you see at once where the planets are in the zodiac. To find the houses, count from the lagna box clockwise.

#The North Indian chart

In the North Indian style, the houses are fixed and the signs move. The chart is a square with its diagonals and a diamond drawn inside. The top central diamond is always the first house; the houses go round anticlockwise. The number of the sign in each house is written in it (1 for Aries, 2 for Taurus, and so on).

The layout is easiest to learn as a rule:

• the top centre diamond is house 1;
• going anticlockwise, the next triangles and diamonds are houses 2, 3, 4 … 12;
• the left centre diamond is house 4, the bottom centre diamond is house 7, the right centre diamond is house 10;
• each house shows the number of its sign.

In our example the top diamond shows 7 (Libra) and the lagna; house 10 (right centre) shows 4 (Cancer) with the Sun, Jupiter, Venus and Ketu; house 7 (bottom centre) shows 1 (Aries) with Mars; and so on. The kundli page of this website draws both the South and North Indian charts for any birth.

#The East Indian chart

In Bengal, Odisha and Assam a third style is common. Like the South Indian chart, it fixes the signs, but it places Aries in the top centre box and runs anticlockwise. Once you can read the other two, it takes only a minute to learn.

#Step 6: Record the panchanga of the birth

A traditional horoscope always records the five limbs of the birth moment (Chapter 5). For our example, worked out from the positions above:

The person's birth star is Rohini, ruled by the Moon (Chapter 4). That single fact decides the start of their Vimshottari planetary periods (Chapter 22).

Traditional horoscopes also give the time of birth in ghatis after sunrise. Here: 4 h 31 m 08 s after sunrise = 271.1 minutes ÷ 24 = 11 ghatis 18 vighatis.

#A checklist for every chart

Before you read any chart — one you cast yourself, one a program prints, or one a family hands you — check:

1. Date, time, a.m./p.m., place, time zone, and any war time or summer time.
2. Ayanamsa (which one?) and node (mean or true?).
3. Mercury within 28° and Venus within 47° of the Sun.
4. Rahu and Ketu exactly opposite.
5. The lagna roughly where it should be: at sunrise the lagna is in the Sun's sign; at noon it is about three signs ahead of the Sun; at sunset about six signs ahead; at midnight about nine. (In our example, birth was 4½ hours after sunrise, and the lagna is in Libra, three signs ahead of the Sun's sign Cancer. That fits.)
6. The birth star agrees with what the family remembers, if they know it.

#Summary

• A chart shows the grahas' sidereal positions and the rising sign (lagna) for one moment and place.
• Most errors come from the birth data: check a.m./p.m., the clock (IST, local time, war time 1942–45), the place and the time zone.
• Planet positions come from an ephemeris; subtract the ayanamsa to make them sidereal.
• The lagna can be found by hand: at sunrise it is (almost) the Sun's position; then step forward through the signs by their rising times (Surya Siddhanta III.42–48). Each four minutes of time moves it about one degree.
• In the classical method the whole sign of the lagna is the first house and the following signs are the following houses (Brihat Jataka I.15–19).
• Charts are drawn in the South Indian style (signs fixed), the North Indian style (houses fixed) and the East Indian style.
• A full horoscope also records the panchanga of the birth moment and the birth star.

#Exercises

1. A birth is recorded as 6:45 a.m. on 10 March 1944 in Chennai, IST. What was the time in UT?
2. A family record says "born at 18 ghatis after sunrise", and sunrise that day was at 6:20. What was the clock time?
3. A person is born in a town at 75°30′ E. How many minutes is local mean time behind IST?
4. In the example chart, which house is Mercury in? Which house holds Saturn?
5. A program prints a chart with the Sun at 10° Aries and the lagna in Capricorn, for a birth at 7 a.m. Something is probably wrong. What?
6. Draw the example chart in the South Indian style from memory, then check it against this chapter.

Answers: 1. In 1944 India was on war time, 6 h 30 m ahead of UT: 6:45 − 6:30 = 00:15 UT. 2. 18 × 24 = 432 minutes = 7 h 12 m; 6:20 + 7:12 = 13:32. 3. 82°30′ − 75°30′ = 7°; 7 × 4 = 28 minutes. 4. Mercury in Leo, the 11th house; Saturn in Sagittarius, the 3rd. 5. At 7 a.m. the lagna should be in or near the Sun's sign (Aries or Taurus); Capricorn is about three signs behind, which is where it would be about six hours earlier, around 1 a.m. — check a.m./p.m. or the time zone.