Tian Ku: Rat on Horse, Ku back and Xu on

Start on Horse, then take the rhyme line by line

Tian Ku (天哭) is one of the few year-based minor stars whose placement the Zi Wei Dou Shu Quan Shu writes out in full, and the same rhyme governs Tian Xu (天虚) as well:

Tian Ku and Tian Xu start at the Horse palace. From the Horse palace set the Rat; the two tracks part. Ku goes back from the Snake, Xu goes on from the Goat. Count to the birth year and it settles there.

Each of the four lines has its own job. The first gives the start: both stars set out from the Horse palace. The second says that the Rat year is the one placed there. The third separates the tracks: Tian Ku goes back toward the Snake, Tian Xu goes on toward the Goat. The fourth closes: count to the birth-year branch, and the star settles on it.

Open the full-size diagram

Comparison table: spots counted from the juan 2 rhyme "Tian Ku and Tian Xu start at the Horse palace" and matched cell for cell by charting all twelve year branches in iztro 2.6.0; the three marked cells come from the "Ox, Rabbit, Monkey palaces" line of juan 1.

Each column of the table is a year branch. In a Rat year nobody moves and both stars sit on Horse. In an Ox year Tian Ku has stepped back to Snake and Tian Xu forward to Goat; in a Tiger year they are on Dragon and Monkey, and so on, one more step each year. Charting all twelve year branches in the engine gives exactly the cells the rhyme counts out.

One example to walk the rhyme

Three neighboring year branches turn the four lines into moves:

By the Rabbit year Tian Ku lands on Rabbit and Tian Xu has reached Rooster; afterwards Tian Ku keeps running backward and Tian Xu forward. After twelve years each star has circled back to its start.

The Rat-Horse line as a mirror

Put the two positions on the ring and the rhyme shows something it never says: within one year branch, Tian Ku and Tian Xu are always mirror images across the line from Rat to Horse. Whatever one gives up in steps, the other gains.

In numbers: Rat is 0, Ox is 1, up to Pig as 11. The number of Tian Ku is 6 minus the year number, and Tian Xu is 6 plus it, so the two always add up to a multiple of twelve. The mirror's two ends coincide in only two cases: the Rat year, number 0, and the Horse year, number 6, when both stars share a branch.

The three palaces the first juan names

The juan 1 answer on Tian Ku and Tian Xu is mainly a run of heavy remarks, with its conditions hung on position and companion stars. Just one line gives positions directly:

The Ox, Rabbit and Monkey palaces are fortunate.

To turn Ox, Rabbit and Monkey into birth-year branches the two stars have to be counted separately:

So "Ox, Rabbit, Monkey" are three branches only, and the birth years they correspond to depend on which star is meant. None of the other heavy remarks in the answer is carried over as a conclusion about anyone.

Five charts: from year branch to palace

Five sample charts run the whole way: the year sets the branch, Life sets the palace name.

Charts 1 and 2 show the two cases of sharing described above: Jia Zi (甲子) puts both on Horse, Geng Wu (庚午) puts both on Rat. In chart 3, a Wu Chen (戊辰) year, Tian Ku has reached Tiger and Tian Xu Dog, with Life on Pig; counting back from Pig, Tiger is Property and Dog is Siblings. In chart 5, Xin Wei (辛未), Tian Ku lands on Pig, the very branch of Life, so its palace is Life.

1. 1

   Fix the year branch

   Take it by the year boundary the chart uses; under another boundary the year branch may differ.

2. 2

   Count Ku back and Xu on

   The Horse palace holds the Rat year; Tian Ku runs back toward the Snake and Tian Xu on toward the Goat, until the birth-year branch.

3. 3

   Count the palaces from Life

   From the Life branch walk backward through the branches to each star; that gives the palace each one is in.

Its partner, Tian Xu, has a page of its own; the palace order is in the twelve palaces, how Life is found in the Life and Body palaces, and the wider classification of minor stars in auxiliary, malefic and minor stars.