Apostrophe

"Bright star, would I were steadfast as thou art-"

In his poem "Bright Star," John Keats uses apostrophe to directly address the star. Keats uses apostrophe instead of a description of the star to symbolize the everlasting nature of a heavenly body.  The speaker in the poem longs to be like the star.  So, the use of apostrophe also emphasizes the qualities of the star that the speaker wishes emulate and those he does not want to emulate.  The speaker wants to be steadfast like the star.  But on the other hand, he does not want to be alone.  He longs to be "pillowed upon my fair love's ripening breast;" he longs for love.  His two desires are to be eternal like the stars, but also experience love. However, these two desires do not go together, which he shows awareness of in the last line:  "And so live ever-or else swoon to death."