Revelation 1:20

"The mystery of the seven stars which you saw in My right hand,... The seven stars are the angels of the seven churches."

In this verse, angels are referred to symbolically as "stars."


Revelation 12:3,4,9

"And another sign appeared in heaven: behold, a great, fiery red dragon....  His tail drew a third of the stars of heaven and threw them to the earth.... So the great dragon was cast out, that serpent of old, called the Devil and Satan, who deceives the whole world; he was cast to the earth, and his angels were cast out with him."

These verses allude to the war in heaven when Satan (symbolically portrayed here as a "dragon"), and one third of the angels (symbolically referred to again as "stars") who sided with him were cast out of heaven.