This line opens with the word “no,” which reinforces the speaker’s claims about how he does not want to be like the star. The word “yet” here marks the beginning of a new idea. The speaker repeats his desire to remain “steadfast” and then goes on to explain what he means by this and why he desires it.
Notice that the em-dash preceding this line is followed immediately by the word “not.” One function of the em-dash is to signal an abrupt turn in thought. Here, even though the speaker has just expressed his longing to be like the “bright star,” this turn signals to the reader that he will first tell us all of the ways in which he does not want to be like a star before elaborating on what he means by “would I were.”
