8:11 and the name of the star is called Wormwood; and a third of the waters became wormwood; and many men died from the waters, because they were made bitter.

and the name of the star is called WORMWOOD;

The plant, Artemisia absinthium, is known as wormwood. From it, a dark green oil, which is very bitter, is produced. It is lethal in water as the rest of the verse shows.

a THIRD of the waters became WORMWOOD; and many men died from the waters, because they were made bitter.

There are two literal possibilities:

  1. There is an "explosion" of the wormwood plant on the earth which, when the previous two trumpets judgment is completed, has been compressed or crushed to release the wormwood oil into a THIRD of the waters.

  2. Since this is a star, the chemical composition, on impact, is such as to pollute the THIRD of waters and make them bitter. Consider that the Russian word, Chernobyl means Wormwood.

The symbolic view is that if this is the devil and his followers who are being thrown from heaven, then he brings bitterness and death.

Wormwood as bitterness
Deuteronomy 29:18 Forsaking the covenant brings ....
Proverbs 5:4 What an adulteress is in the end.
Jeremiah 9:13-15 Forsaking the Law brings ...
Jeremiah 23:15 What false prophets can look forward to ...
Lamentations 3:15-19 How solitary real prophets sometimes feel!
Amos 5:7 Subverted justice
Amos 6:12-14 The fruit of righteousness is turned into ..

This trumpet is a direct judgment upon mankind because many men died from the waters; the previous two trumpets were upon the earth itself with man involved as an "innocent" bystander.