《晋书·志·第一章》
它西面天河中的杂颗星像勾子的形状，叫勾星，若成一直线，就会发生地震。
其西河中九星如钩状，曰钩星，直则地动。
The miscellaneous stars in the Milky Way on its west side are shaped like hooks, called Gouxing. If they form a straight line, an earthquake will occur.