A part
星
Shown as a part of 3 words so far, read one way.
せい 3 words
- 衛星えいせいsatellite
衛星 · here “celestial body”
- 惑星わくせいplanet
惑星 · here “star”
Also written with 星
These words contain the character in their spelling but show no breakdown that names it, so nothing is claimed about its role in them.