The name of the star is Wormwood. A third of the waters turned bitter like wormwood oil, and many people died from the bitter waters.

Jeremiah 9:15
Therefore this is what the LORD of Hosts, the God of Israel, says: "Behold, I will feed this people wormwood and give them poisoned water to drink.

Jeremiah 23:15
Therefore this is what the LORD of Hosts says concerning the prophets: "I will feed them wormwood and give them poisoned water to drink, for from the prophets of Jerusalem ungodliness has spread throughout the land."

Zechariah 13:8
And in all the land, declares the LORD, two-thirds will be cut off and perish, but a third will be left in it.

Zechariah 13:9
This third I will bring through the fire; I will refine them like silver and test them like gold. They will call on My name, and I will answer them. I will say, 'They are My people,' and they will say, 'The LORD is our God.'"

Revelation 8:7
Then the first angel sounded his trumpet, and hail and fire mixed with blood were hurled down upon the earth. A third of the earth was burned up, along with a third of the trees and all the green grass.

Revelation 9:15
So the four angels who had been prepared for this hour and day and month and year were released to kill a third of mankind.

Revelation 9:18
A third of mankind was killed by the three plagues of fire, smoke, and sulfur that proceeded from their mouths.

Revelation 12:4
His tail swept a third of the stars from the sky, tossing them to the earth. And the dragon stood before the woman who was about to give birth, ready to devour her child as soon as she gave birth.

And the name of the star is called Wormwood: and the third part of the waters became wormwood; and many men died of the waters, because they were made bitter.