Revelation 8:11-12

11The name of the star was Bitterness. It made one-third of the water bitter, and many people died from drinking the bitter water.

12Then the fourth angel blew his trumpet, and one-third of the sun was struck, and one-third of the moon, and one-third of the stars, and they became dark. And one-third of the day was dark, and also one-third of the night.