An ordinary star on an elegant mountain
Xin is a heavenly stem, the right hand mountain of the Dui trigram, You at 270 degrees on one side, Xu at 300 on the other. It is metal, and a grave that sits Xin faces Yi at 105 degrees. The Tianxing ring prints Tianyi across the Xin band.
Two labels meet here and they are not the same thing. Tianyi is the star, and it ranks as ordinary. Six elegant is a rank of the mountain, shared with Gen, Xun, You, Bing and Ding. The school keeps them apart: the mountain's rank says a peak here is worth a close look; the star's name only carries the imagery the old maps left on that bearing, a helper, a patron.
What Tianyi confirms and what it leaves alone
When the range enters through Xin alive, with rises, turns and a narrow neck before the head, the school writes it down as a Xin range under Tianyi and the reading goes on. When a peak on Xin is tall, whole and upright from the cave, it is an elegant peak confirmed by the star. Water that comes in from Xin and bends toward the site gets the same note.
In each case the star is a stamp on a page already written by the ground. If the range is flat and broken, Tianyi does not lift it. The Cui guan pian answers dragon, cave, sha and water with the stars in turn, and in all four the ground speaks first.
What this means on the ground
Tianyi sits on the Tianxing ring between Shaowei on You and Tiankui on Xu. At a grave, stand behind the stone, sight along its face, and turn the line to each peak on the west by north west. A needle between 277.5 and 292.5 puts the peak on Xin. Near 278 or 292 you are on a border: read three times and note the side.
At a house or shop, stand inside the door, back to it. On the Xin bearing, a whole, upright building or hill is a good sha and the star agrees. A gap, a sharp corner pointed at the door or a road running straight in is a poor sha, whatever the ring says.
Common mistakes
Reading the ring with a phone app: the app gives a bearing; the Tianyi name belongs to this school's luopan. Taking the name as a verdict: a patron star does not deliver a patron, and the school does not read it that way. Looking at the star before the landform: a Xin peak counted on the ring but never walked around can hide a cut face on its far side. Measuring from a satellite map: the screen gives true north, the luopan gives magnetic north, and the Xin band is only 15 degrees wide.
Questions people ask
What does the Tianyi star mean in feng shui?
In the Tianxing school Tianyi is the star on the Xin mountain, 285 degrees. Its name is the star of the Tianyi noble person, with the imagery of help from others. It is an ordinary star: it confirms a good Xin range or peak and adds nothing of its own.
Is Xin a good direction on the luopan?
Xin is one of the six elegant mountains, so a clean peak on it is well regarded. Direction alone says nothing. What is on that bearing, and how the range and water behave, decides it.
What is the difference between Tianyi and Shaowei?
They sit on neighbouring mountains. Shaowei is on You at 270 degrees and is one of the four noble stars. Tianyi is on Xin at 285 degrees and is ordinary. A peak near 277.5 degrees needs three careful readings before it is named.
If a peak or a range sits on the Xin bearing at your site, have Master Zhang read it on the Tianxing ring, or learn to do it yourself on the field course.