Gan De quotes:

Every 12 years Jupiter returns to the same position in the sky; every 370 days it disappears in the fire of the Sun in the evening to the west, 30 days later it reappears in the morning to the east...[Observation in 4th century B.C.]

Jupiter was very large and bright. Apparently, there was a small reddish star appended to its side. This is called "an alliance."

In the year of chan yan..., Jupiter was in [the Zodiacal Division of] Zi, it rose in the morning and went under in the evening together with the Lunar Mansions Xunu, Xu and Wei. It was very large and bright. Apparently, there was a small reddish (chi) star appended (fu) to its side. This is called "an alliance" (tong meng).