Northern Black Tortoise · 11
Xu Ri Shu（Emptiness Mansion）
Xu Ri Shu is the traditional deity title for Emptiness Mansion, number 11 in the atlas and part of the Northern Black Tortoise. It follows Girl Mansion and precedes Rooftop Mansion. This Chinese Medieval reconstruction contains 2 stars and 1 segments; HIP 106278 is the red-ringed reference star.
Asterism reference
- Position in the atlas
- 11 / 28
- Four Symbols group
- Northern Black Tortoise
- Stars in this diagram
- 2
- Determinative star
- HIP 106278
Reading this star map
Emptiness is a two-star, one-line pattern in this version. The red ring lies at lower left and the other star at upper right. This simple example separates an asterism from a mansion region: the line shows a visual relation, not the full boundary of the region.
Understanding the deity title
The traditional title 虛日鼠 (Xu Ri Shu) combines the mansion character 虛, the association 日, and the animal image 鼠. The astronomical entry is Emptiness Mansion. A deity portrait expresses cultural imagery; a star map records positions and connecting lines. They can be read together without expecting the star pattern to resemble the animal.
What does this calculator result mean?
If a birthday lookup returns this mansion, the entered date is assigned to it by our daily almanac rules. It does not mean everyone born that day shares a personality, or that the Moon was inside this star pattern. Compare calendar, date and assignment system before comparing tools.
Twenty-Eight Mansions sculptures · Fucheng Jade Emperor Temple, Jincheng
Photo: Patrick20242023. Resized and compressed; Shen Shui Yuan is also cropped to isolate the figure.
Original photographs · CC BY-SA 4.0Further reading: personality associations
The historical text describes the roles of celestial asterisms. The life and personality associations below are our modern interpretations, not historical claims about people born on a particular date.
「主北方邑居廟堂祭祀祝禱事，又主死喪哭泣」《晉書》卷十一・天文志上・二十八舍Xu is associated with rites, prayer and mourning. A modern interpretation is taking endings seriously: giving a relationship or a period of life a proper farewell. Keeping a meaningful object can give memory a place, without making one person responsible for carrying everyone's grief indefinitely.
Sources and image credits
The National Astronomical Observatory of Japan explains the classifications and calendar concepts. Star lines follow Stellarium Chinese Medieval, with positions from HYG v4.1. Our diagrams are attributed under CC BY-SA 4.0 and represent one reconstruction, not the only historical depiction.