TL;DR: La Hầu and Kế Đô in the Vietnamese Cửu Diệu system are the two intersection points of the Moon's orbit, corresponding to the North Node and South Node in modern astronomy. Solar and lunar eclipses occur only when the new or full Moon is near these two points. Three traditions, Indian, Vietnamese and Western, look at the same astronomical entity but assign it different meanings.
What are La Hau and Ke Do in astronomy and in folk belief?
La Hau and Ke Do are the names used in the Vietnamese Cuu Dieu (nine luminaries) system for two points on the Moon's orbit, corresponding to the North Node and the South Node in modern astronomy. They are not real celestial bodies but two geometric points on the orbit, where the Moon crosses the ecliptic plane.
The Moon's orbit is inclined by about 5 degrees to the ecliptic plane, so it crosses this plane at two points called the ascending node (North Node) and the descending node (South Node). A solar eclipse occurs when the Moon is near one of these two nodes at the new moon, while a lunar eclipse occurs when the Moon is near a node at the full moon. The two nodes are not fixed: they regress along the ecliptic, completing one circuit in about 18.6 years. Because eclipses are tied to these points, Indian astrology personified them as Rahu and Ketu, beings that obscure the Sun and the Moon.
In Sanskrit, Rahu is the ascending node and Ketu is the descending node. The occult book Numbers: Their Occult Power and Mystic Virtues by W. Wynn Westcott (1911) lists the Sanskrit names of the seven planets in Hindu astrology, then calls Rahu the upper and Ketu the lower node of the Moon[1].
Which stars make up the Vietnamese Cuu Dieu, and in what order?
Cuu Dieu is a system of nine stars that the Vietnamese use to calculate the star governing each year, comprising La Hau, Tho Tu, Thuy Dieu, Thai Bach, Sun, Van Hon, Ke Do, Moon, and Moc Duc.
The star of the year is calculated from nominal age as follows: for men, it begins with La Hau at the age of 10 (in nominal age, tuổi mụ); for women, it begins with Ke Do at the age of 10, then follows the order Ke Do, Van Hon, Moc Duc, Moon, Tho Tu, La Hau, Sun, Thai Bach, Thuy Dieu. The star of the year is obtained by taking (nominal age minus 10) divided by 9, taking the remainder, and then matching it against the corresponding order table for men or women. This method produces a 9-year cycle.
The order of the nine stars for men and women:
| Order | Men (from nominal age 10) | Women (from nominal age 10) |
|---|---|---|
| 1 | La Hau | Ke Do |
| 2 | Tho Tu | Van Hon |
| 3 | Thuy Dieu | Moc Duc |
| 4 | Thai Bach | Moon |
| 5 | Sun | Tho Tu |
| 6 | Van Hon | La Hau |
| 7 | Ke Do | Sun |
| 8 | Moon | Thai Bach |
| 9 | Moc Duc | Thuy Dieu |
Men and women follow two different sequences: the women's order is not the men's order with a different starting point. After Ke Do, for example, men meet Moon while women meet Van Hon.
Why are La Hau and Ke Do considered unlucky stars in folk belief?
In Vietnamese folk belief, La Hau and Ke Do are considered two unlucky stars, often associated with calamity, illness and unexpected events. This view is commonly explained by the belief that the two stars cause solar and lunar eclipses.
In ancient Indian astronomy, the nine grahas (the nine luminaries) were the Sun, the Moon, the five planets Mercury, Venus, Mars, Jupiter and Saturn, plus Rahu and Ketu; Rahu and Ketu were pictured as beings that cover the Sun and the Moon during eclipses. Modern astronomy shows that they are only two geometric points, not objects.
In folk belief, a person who "meets" the star La Hau or Ke Do in a given year is considered to be in a year of misfortune. Le Duc Hanh's article on the practice of cúng sao giải hạn (star worship to ward off misfortune) states: "On the 8th of each month the pagoda organises giải hạn (rite to ward off misfortune) collectively for those who have the La Hau star in the year, on the 15th (full moon day) for the Thai Bach star, and on the 18th it holds a rite to ward off misfortune for the Ke Do star."[2]
How did the Cuu Dieu system spread from India to Vietnam?
The ancient Indian calendar, which the Chinese called the Fan calendar, was transmitted to China along with Buddhism.
The nine luminaries (navagraha) of Indian astrology reached China through Buddhist scriptures, especially Tantric texts of the Tang dynasty. These texts carried not only rituals but also the system of star calculation and their meanings. From China, this system spread to Vietnam, Japan and Korea. In Vietnam, Cuu Dieu was integrated into folk belief and became part of the rite of cúng sao giải hạn (star worship to ward off misfortune).
The Cuu Dieu system itself is of Indian origin, while the Vietnamese way of using it (calculating stars by nominal age, rites to ward off misfortune) is a later cultural adaptation; not every detail of the star worship ceremony comes from India.
How are the North Node and South Node understood in Western astrology?
In modern Western astrology, the North Node and South Node are usually interpreted as the direction of growth and the lessons of the past. They are not regarded as unlucky stars but as the two poles of an axis of development.
Western astrology inherited Greek and Arabic astrology. In the Tetrabiblos, Ptolemy treats the zodiacal position of a solar or lunar eclipse as something to note when judging its effects on nations. Medieval European astrology, drawing on Arabic astrology, called the North Node the Dragon's Head (Caput Draconis) and the South Node the Dragon's Tail (Cauda Draconis).
Reading the North Node as the direction of growth and the South Node as the starting point became common in Western astrology from the 20th century, especially in psychological astrology. This understanding differs from the Indian and Vietnamese views, where La Hau and Ke Do are usually regarded as unlucky stars.
Are La Hau and Ke Do always a bad omen?
Not necessarily. In Indian astrology, Rahu and Ketu can carry favourable or unfavourable meanings depending on their position in the chart.
Indian astrology classes Rahu and Ketu as the two shadow planets (chāyā graha). Interpretive texts link Rahu with desire and illusion, and Ketu with loss but also with letting go and liberation (moksha).
In Vietnam, La Hau and Ke Do are still regarded as unlucky stars, and the rite to ward off misfortune is how people seek to neutralise them.
